Question

So confused!!! Can you guys please help!!!!




If f(x) varies directly with x2, and f(x) = 75 when x = 5, find the value of f(4).

A.
100

B.
50

C.
48

D.
25

Answer 1

Ummm ii think it is B but i might be wrong lol

Answer 2

k

Answer 3

cool

Answer 4

Lol but i need to make sure

Answer 5

\[f(x)=k\times x^2\]
\[f(5)=75=k\times 5^2\]
\[75=25k\] find \(k=3\) and so \[f(x)=3\times x^2\]

Answer 6

then
\[f(4)=3\times 4^2=3\times 16\]

Answer 7

Thanks @satellite73