Question

The function f(x) varies directly with x and f(x) = 56 when x = 8

evaluate f(x) when x = 2
A. 4 B. 7 C. 8 D. 14

Answer 1

Let f(x) = kx

f(8) = 56
⇒ k * 8 = 56
⇒ k = 56/8 = 7

thus f(x) = 7x

f(2) = 7 * 2 = 14

Answer is D.

Hope it helps!

Answer 2

1) D
f(8)=8*a
12=8*a
a=12/8=3/2

2) D
f(8)=8*a
56=8*a
a=56/8=7
f(2)=7*2=14

3) y=6/x