Question

If y varies directly as x and y =15 when x=3, find y when x=12.

Answer 1

y varies directly with x means y = k*x for some number k
now we need to find that number k
we know when x = 3, y = 15
so
let x = 3, y = 15
15=k*3
k=5
so
y=5*x
we need y when x = 12
y = 5*12 = 60

Answer 2

Thank you :)