math homework

Paul,

If all you are looking for is an equation that solves the max/min heights then you have a simple equation.

Y = height, x = 5, b = 13

Y= b ± x

Y= 13 ± 5

Ymin = 13 - 5 = 8

Ymax = 13 + 5 = 18

Heights range from 8 to 18 km.

Ed