The domain is (1,3,5,7,9) and the range is (2,4,6,8,0)
From the information obtained from the question, two equations can be created:
Let x and z be the two numbers (parts)

. . . . (1)

. . . . (2)
By transposing (2), make 'z' the subject of the equation

. . . . (3)
By substituting (3) into equation (1) to find a value for x




⇒

∴ either

OR

Thus x = 5 or x = 10
By substituting the values of x into (2) to find z
z + (5) = 15 OR z + (10) = 15
⇒ z = 10 OR z = 5
So, the two numbers or two parts into which fifteen is divided to yield the desired results are 5 and 10.
10. 150
11. 1250
12. 105
13. 158000
15. B
Answer: 31.25%
Step-by-step explanation: To answer the question <em>what percent of 80 is 25</em>, we translate the question into an equation.
So we have "what percent" that's x, "of 80" means times 80, "is 25" = 25.
Now to solve for <em>x</em>, since <em>x</em> is being multiplied by 80, we need to divide by 80 on both sides of the equation. On the left side of the equation the 80's cancel and we have <em>x</em> and on the right side of the equation, we have 25 ÷ 80 which gives us 0<em>.</em>3125. Now, remember that we want to right our answer as a percent so to write 0.3125 as a percent, we move the decimal point 2 places to the right and we get 31.25%.
Therefore, 31.25% of 80 is 25.