Question

A varies directly as r^2 if a = 12 when r = 2 calculate a when the value of a r = 5 and the value of r when a =48

Answer 1

a = kr^2

since a/r^2 is constant, you want
a such that a/5^2 = 12/2^2
r such that 48/r^2 = 12/2^2

Answer 2

a.75 b.plus or minus 4