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

A. 12

B. 6

C. 8

D. 3

Question

If f(x) varies directly with x, and f(x) = 48 when x = 8, find the value of f(x) when x = 2

A. 12

B. 6

C. 8

D. 3

anonymous · Answer

i think its b im  not sure though

hexagon001 · Answer

b

hexagon001 · Answer

because 6x8=48

terenzreignz · Answer

@hexagon001 
Not looking for the constant of proportionality, rather, the value of f(x) when x = 2 ;)

hexagon001 · Answer

ahh reading too fast and i end up missing the ending

hexagon001 · Answer

so itll be A

terenzreignz · Answer

Just so you know what you're doing, @Cookie_009 
If a and b are two values that vary directly, then that only means

a = kb
for some constant k.

So, it's given that f(x) varies directly with x, so it means
f(x) = kx, for some constant k, right?

anonymous · Answer

yep

terenzreignz · Answer

Okay :)
So, when x is 8, f(x) is 48, right?

anonymous · Answer

yes

terenzreignz · Answer

So...
f(x) = kx
48 = k(8)
right?

anonymous · Answer

yess

terenzreignz · Answer

Well
48 = 8k
It's just a matter of finding k :)