Question

If f(x)=5x^2+3x-1How do I calculate f(4)= ?

Answer 1

Given

$f\mleft(x\mright)=5x^2+3x-1$

To find: The value of f(4).

Explanation:

It is given that,

$f\mleft(x\mright)=5x^2+3x-1$

That implies,

Put x=4.

Then,

$\begin{gathered} f\mleft(4\mright)=5(4)^2+3(4)-1 \\ =5\times16+12-1 \\ =80+12-1 \\ =92-1 \\ =91 \end{gathered}$

Hence, the value of f(4) is 91.