Which ratios form a proportion?

a. 4/9 , 12/25
b.3/7, 18/42
c. 5/11, 20/45
d.5/8, 15/25

How do i put 3(x+7) in distributive property

Af jewelry box is in the shape of a rectangular prism with an area of 528 cube inches. the length of the box is 12 inches and the height is 5 1/2 inches. what is the width of the jewelry box

Given that sin∅ = 1/4, 0 < ∅ < π/2, what is the exact value of cos∅? a. (√4)/4 b. (√15)/4 c. (4π)/2 d. (4√2)/4