Which of the following statements contain a variable? check all that apply. a. the number of people added to the group. b. half the area of the roof. c. sixteen feet long. d. she ran 40 yards

yes

step-by-step explanation:

yes

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