To determine whether students at Bernal want to attend an art festival at the school, Manuel surveys all the students in the library at lunch. Biased or unbiased. Explain for brainlist, no links or report.

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

2 over 5 and 4 over 15

don’t know last one sorry

step-by-step explanation: