If x varies directly as​ y, and x=20 when y=5​, find x when y=8.

Answer 1

If x varies directly as y, y = kx

and x = 20 when y = 5, then 5 = k(20) and k = 5/20 = 1/4

then when y = 8 you have 8 = 1/4 (x) multiply by 4 and

32 = x