jessica increases the temperature of a block of ice by 20. which interger represents the amount by which jessica must change the temperature for the block of ice to return to its starting temperature. ANSWERS= A= -40 B= -20 C= 20 D= 40

C

Step-by-step explanation:

it says she increased it by 20, so if you take away the same amount that she added then it should be at the same number she started at

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15