Please help! A chemist has 100ml of 25% acid solution. How much of the solution does she need to drain and replace with 70% acid solution to obtain 100ml of 60% acid solution?

Answer:

109 square feet.

Step-by-step explanation:

109 in: = 109/12 = 9.0833333.... = 9 5/60 = (540+5)/60 = 545/60

Area = L*w

L = 545/60 feet

W = 12 feet

Area = 545/60 *  12

Area = 545*12/60

Area = 545 /5 = 109 square feet.  

Answer:

109

Step-by-step explanation:

Answer:

5 large boxes

3 small boxes

Step-by-step explanation:

Create two equations to represent the problem.

let "a" be the number of small boxes

let "b" be the number of large boxes

20a + 40b = 260    This equation shows the numbers of books

a + b = 8                  This equations shows the number of boxes

Solve the system of equations (solve for a and b). We can solve using the substitution method.

Rearrange a + b = 8 to isolate one of the variables.

a = 8 - b    New equation that represents "a"

Since we know an equation for "a", we can substitute what "a" equals into the other equation. There will only be one variable in the equation, so we can solve by isolating. Isolate by doing reverse operations.

Substitute "a" for 8 - b

20a + 40b = 260

20(8 - b) + 40b = 260     Distribute 20 over the brackets by multiplying

160 - 20b + 40b = 260    Collect like terms (numbers with same variables)

160 + 20b = 260    Start isolating "b". Subtract 160 from both sides

20b = 260 - 160

20b = 100    Divide both sides by 20

b = 5    Number of large boxes

Substitute "b" for 5 in the simplest equation

a + b = 8

a + 5 = 8      Subtract 5 from both sides to isolate "a"

a = 8 - 5    

a = 3      Number of small boxes

Therefore there were 5 large boxes and 3 small boxes sent.

Answer:

s = the number of small boxes

L = the number of large boxes

System of Equations:

25s+40L=250

s+l=7

Step-by-step explanation:

Answer:

C

Step-by-step explanation:

∠ AFD = ∠ AFC + ∠ CFD

Given ∠ CFA = 90° and

∠ CFD = 90° - ∠ EFD, that is

∠ CFD = 90° - 62° = 28°, thus

∠ AFD = 90° + 28° = 118° → C

Answer:

answer is c. 118

angle AFC+ angleCFD = angle AFD..

[ANGLE AFD =AFC + CFD][ANGLE CFD = 90 -62 ]

Answer:

Step-by-step explanation:

[tex]\left\{\begin{array}{ccc}x=y-2&(1)\\-3x+3y=6&(2)\end{array}\right\qquad\text{substitute (1) to (2)}\\\\-3(y-2)+3y=6\qquad\text{use the distributive property}\\-3y+6+3y=6\qquad\text{combine like terms}\\(-3y+3y)+6=6\\6=6\qquad\bold{TRUE}\\\\\text{That is why the system of equations has infinitely many solutions.}[/tex]

Answer:

80 years old

Step-by-step explanation:

the ratio is 1:10 and their total is 88. Just by looking at it you can see that Geoff's age is 8 and Eathan is 80. The total is 88 and the ratio also matches.

1:10  1 times 10 is 10

8:80 8 times 10 is 80

Answer:

hi there!

The correct answer to this question is: 80 years old

Step-by-step explanation:

you first need to set up to equations:

in this case: I will use the variable "e" for Ethan and "g" for Geoff

e=10g

g + e = 88

since e = 10g, substitute that into the second equation and you get 10g + g = 88

you add the variables and you get 11g=88 then you divide 11 on both sides and you get 8 so geoff is 8

then you plug 8 back into the second equation and you get ethan's age which is 80

The value of "x" is [tex]\frac{-5}{2}[/tex]

Solution:

Given f(x) = 4x - 6

g(x) = 8x + 4

To find: value of x when f(x) = g(x)

We can equate f(x) and g(x) as per given statement and solve for x

f(x) = g(x)

Substituting the values of f(x) and g(x) in above expression,

4x - 6 = 8x + 4

4x - 8x = 4 + 6

-4x = 10

On solving,

[tex]x = \frac{10}{-4}\\\\x = \frac{-5}{2}[/tex]

Thus value of "x" is [tex]\frac{-5}{2}[/tex]

Answer:

[tex]\large\boxed{C=2\pi r}[/tex]

Step-by-step explanation:

A linear equation is an equation in which a variable is in the first power.

The formula of a Circumference of a circle

[tex]C=2\pi r\\\\2,\ \pi-\text{numbers}\\r-\text{variable}\\\\\boxed{\bold{YES}}[/tex]

The formula of an Area of a circle

[tex]A=\pi r^2\\\\\pi-\text{number}\\r^2-\text{variable in the second power}\\\\\boxed{\bold{NO}}[/tex]

The formula of a volume of a sphere

[tex]V=\dfrac{4}{3}\pi r^3\\\\\dfrac{4}{3},\ \pi-\text{numbers}\\r^3-\text{variable in the third power}\\\\\boxed{\bold{NO}}[/tex]

Final answer:

After calculating that each person bought an average of 4 pounds of cookie dough last year, and using the average predicted sales of 650 people for this year, the math club should prepare approximately 2600 pounds of cookie dough.

Explanation:

The question is asking for an estimation of how many pounds of cookie dough the math club will need to sell this year, given that they predict selling to more people than last year. To calculate this, we need to find the average amount of cookie dough sold per person last year and then multiply that by the predicted number of people for this year.

Last year, the math club sold 2,080 pounds of cookie dough to 520 people. Thus, each person bought an average of
2080 pounds ÷ 520 people = 4 pounds per person.

This year, they are predicting sales to between 630 and 670 people. We will use the average of these two numbers for a better estimation, which is (630 + 670) ÷ 2 = 650 people.

Now, we multiply the average amount of dough per person by the estimated number of people:

4 pounds per person × 650 people = 2600 pounds.

Therefore, the math club should prepare approximately 2600 pounds of cookie dough for this year's fundraiser.

Answer:

y - 2 = x + 3

y = x + 5

-x + y = 5 standard form

Answer: 28.08%

Step-by-step explanation: To find the percent increase, we divide the amount of change by the original number.

The amount of change is the difference between the two numbers which in this case is 561,000 - 438,000 and the original number is 438,000.

561,000 - 438,000 is 123,000 so we are left with 123,000 divided by 438,000 which is 0.2808. Finally, since our problem is asking us for a percent, we write 0.2808 as a percent by moving the decimal point two places to the right to get 28.08%.

So when the population changes from 438,000 to 561,000, it has increased by 28.08%.

Answer:

Volume of the rectangular prism is given by,

[tex]\frac {15}{2x}[/tex] unit .

Step-by-step explanation:

According to the question,

height of the prism = [tex]\frac {5}{2x + 8}[/tex] unit = h (say)

depth of the prism = [tex]\frac {x + 4}{4}[/tex] unit = w (say)

length of the prism = [tex]\frac {12}{x}[/tex] unit = l (say)

So,

the volume of the rectangular prism,

V = lwh

   = [tex]\frac {5}{2x + 8} \times \frac {x + 4}{4} \times \frac {12}{x}[/tex] unit

   =  [tex]\frac {15}{2x}[/tex] unit

Answer:

A

Step-by-step explanation:

The weight of wrestler was 80 kg before the special diet

Step-by-step explanation:

Given function is:

[tex]W=80+5.4t[/tex]

We can substitute the values of t to find the weight after t number of months

When we have to find the initial weight , t has to be put equal to zero

So,

[tex]W = 80+5.4t\\t = 0\\W = 80 + 5.4(0)\\W = 80+0\\W = 80[/tex]

Hence,

The weight of wrestler was 80 kg before the special diet

Keywords: Functions, variables

Learn more about functions at:

#LearnwithBrainly

Answer:

80

Step-by-step explanation:

i'm not sure but the answer for people on khan

The larger number is 30 and smaller number is 10.

Step-by-step explanation:

Let,

Larger number = x

Smaller number = y

According to given statement;

The larger number is 20 more than the smaller.

x = y+20    Eqn 1

Four times the larger is 70 more then 5 times the smaller.

4x = 5y+70    Eqn 2

Putting value of x from Eqn 1 in Eqn 2

[tex]4(y+20)=5y+70\\4y+80=5y+70\\80-70=5y-4y\\10=y\\y=10[/tex]

Putting y=10 in Eqn 1

[tex]x=10+20\\x=30[/tex]

The larger number is 30 and smaller number is 10.

Keywords: linear equation, substitution method

Learn more about substitution method at:

#LearnwithBrainly

Option D

Money earned by Marty is $ 16.72

Solution:

Given that, Marty started a lawn mowing business

He kept track of his expenses and earnings in a table

Lawn Mower = - $49.99

Gasoline = - $8.79

Moyer's yard = $ 40

Griffen's yard = $ 35.50

To find: Money earned by Marty

Total money earned = lawn mower + gasoline + moyers yard + griffens yard

Total money earned = -49.99 - 8.79 + 40 + 35.50

Total money earned = -58.78 + 40 + 35.50

Total money earned = -18.78 + 35.50 = 16.72

Thus money earned by Marty is $ 16.72

Answer:

Step-by-step explanation:

7x -5y = -18

Making y as subject

-5y = -7x - 18

Dividing through by -5

y = -7/-5x - 18/-5

y = 7/5x + 18/5

Slope m = 7/5

Intercept b = 18/5

Answer:

A. What is the weight of each type of fruit in decimal form?

Grapes in decimal form = 0.8181 pounds

Bananas in decimal form = 1.75 pounds

Apples in decimal form = 2.8333 pounds

B. Does the weight of each type of fruit in decimal form represent a rational number? Explain.

Of course, each of the weights of the fruits in decimal form represent a rational number. The weights can be expressed as a fraction where both the numerator and the denominator in the fraction are integers, like we checked with 9/11, 1 3/4 and 2 5/6. The denominator in a rational number cannot be zero.

Step-by-step explanation:

1. Let's check the information provided to us to answer the questions correctly:

Janis purchased:

9/11 pounds of grapes

1 3/4 pounds of bananas

2 5/6 pounds of apples

2. What is the weight of each type of fruit in decimal form?

Grapes in decimal form = 0.8181 pounds

Bananas in decimal form = 1.75 pounds

Apples in decimal form = 2.8333 pounds

3. Does the weight of each type of fruit in decimal form represent a rational number? Explain.

Of course, each of the weights of the fruits in decimal form represent a rational number. The weights can be expressed as a fraction where both the numerator and the denominator in the fraction are integers, like we checked with 9/11, 1 3/4 and 2 5/6. The denominator in a rational number cannot be zero.

True!

The Cartesian coordinate system is formed by two perpendicular axes, which are the x-axis and y-axis. In this problem, we are given two lines:

[tex]x=4 \ and \ y=5[/tex]

Since the x and y-axes are perpendicular, then the lines [tex]x=4 \ and \ y=5[/tex] are also perpendicular.

Cartesian coordinate system: https://brainly.com/question/2141683

#LearnWithBrainly

Option B

Profit earned in the entire month is $ 31486

Solution:

Given that At the start of the month, Jodie had sold 885 copies of her new book

At the end of the month, she had sold 1,364 copies of her book

Each book profits $13.97, approximately

To find: profit earned in entire month

Total books earned = 885 + 1364 = 2249

Profit earned from 1 book = $ 13.97 ≈ 14

Therefore profit earned from 2249 books is found by multiplying profit earned from 1 book by 2249

profit earned from 2249 books = Profit earned from 1 book x 2249

profit earned from 2249 books = 14 x 2249 = 31486

Therefore profit earned in the entire month is $ 31486

Answer:

-2, -1 and 1.

Step-by-step explanation:

x^3 + 2x^2 - x - 2 = 0

x^2(x + 2) - 1(x + 2) = 0   Note the  common factors (x + 2) so we have

(x^2 - 1)(x + 2) = 0

(x - 1)(x + 1)(x + 2) = 0      (x^2 -1 is the difference of 2 squares).

x =  -2, -1 and 1.

Answer:

Step-by-step explanation:

first we find the slope using the slope formula : (y2 - y1) / (x2 - x1)

(2,-2)....x = 2 and y = -2

(4,1)...x = 4 and y = 1

now sub

slope = (1 - (-2) / (4 - 2) = (1 + 2) / 2 = 3/2

y = mx + b

slope(m) = 3/2

(4,1)...x = 4 and y = 1

now sub and find b, the y int

1 = 3/2(4) + b

1 = 6 + b

1 - 6 = b

-5 = b

so ur equation is : y = 3/2x - 5 <===

I'm assuming we factor...

The answer is (2a + c)(4a^2 - 2ac + c^2.)

⭐ Please consider brainliest! ⭐

✉️ If any further questions, inbox me! ✉️

(The question that got me to Ace rank!)

Answer:

(2a + c)(4a² - 2ac + c²)

Step-by-step explanation:

8a³ + c³ ← is a sum of cubes and factors in general as

a³ + b³ = (a + b)(a² - ab + b²)

Given

8a³ + c³

= (2a)³ + c³

= (2a + c)((2a)² - 2ac + c²), that is

= (2a + c)(4a² - 2ac + c²)

Step-by-step explanation:

The volume of the shell is the volume of the outer sphere minus the volume of the inner sphere.

V = 4/3 π (r+h)³ − 4/3 π r³

V = 4/3 π (r³ + 3r²h + 3rh² + h³) − 4/3 π r³

V = 4/3 π r³ + 4π r²h + 4π rh² + 4/3 π h³ − 4/3 π r³

V = 4π r²h + 4π rh² + 4/3 π h³

If h = 0.1 r:

V = 4π r² (0.1 r) + 4π r (0.1 r)² + 4/3 π (0.1 r)³

V = 0.4π r³ + 0.04π r³ + 0.00133π r³

V = 0.44133π r³

Using the approximation:

V = 4π r² h

V = 4π r² (0.1 r)

V = 0.4π r³

The approximation is reasonable if h is small compared to r.

You divide the difference of the y-coordinates of 2 points on a line by the difference of the x-coordinates  of those same 2  points.

Best of Luck to you.

Answer:

The width of both rectangles are [tex]\frac{36}{l},\frac{21}{L}[/tex].

Step-by-step explanation:

Given : The area of one rectangle is 36 square  feet. The area of a second rectangle is  21 square feet. The rectangles have the  same width and the dimensions are  whole numbers.

To find : What is the width of  both rectangles?

Solution :

According to question, the two rectangles have the same widths but they have different lengths.

Let the width of both rectangle be 'w'

Let the length of one rectangle be 'l'

Let the length of second rectangle be 'L'

The area of the rectangle is [tex]\text{Area}=\text{Length}\times \text{Width}[/tex]

The area of one rectangle,

[tex]36=l\times w[/tex]

[tex]w=\frac{36}{l}[/tex]

The area of second rectangle,

[tex]21=L\times w[/tex]

[tex]w=\frac{21}{L}[/tex]

The width of both rectangles are [tex]\frac{36}{l},\frac{21}{L}[/tex].

Answer:

g^-1 (x)=1/2x+3/2

Step-by-step explanation:

y=2x-3

x=2y-3

2y=x+3

y=1/2x+3/2

Answer:

x= 9

Step-by-step explanation:

Please see attached picture for full solution.

Answer:

x - 0, 1

y - 2, 15/7

Answer: Stephanie is the fastest

Step-by-step explanation:

Here we have to find who runs faster:

Liz:

[tex]8 ft/s[/tex]

Katie:

[tex]\frac{350 ft}{31 s}=11.29 ft/s[/tex]

Stephanie:

[tex]\frac{1 mile}{388 s}. \frac{5280 ft}{1 mile}=\frac{5280 ft}{388 s}=13.60 ft/s[/tex]

Noah:

[tex]\frac{541 ft}{1 min}. \frac{1 min}{60 s}=9.01 ft/s[/tex]

As we can see after comparing, Stephanie is the fastest, since she travels more distance in less time.