Question

If f(x) varies directly with x and f(x) = 48 when x = 8 find the value of f(x) when x = 2

Answer 1

Here, f(x) = kx

k = f(x)/x
k = 48/8
k = 6

So, when x = 2, 
f(x) = 6 * 2
z = 12

In short, Your Answer would be: 12

Hope this helps!