Someone help and please make sure the answer is right

it's 12

Step-by-step explanation:

5(12) =60

60+17=77

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

no not all of them.

step-by-step explanation:

some of them have a square base.