# How do you evaluate the function j(x)=x^3-7x when x=3?

$6$
$\text{to evaluate substitute x = 3 into } j \left(x\right)$
$\Rightarrow j \left(\textcolor{red}{3}\right) = {\left(\textcolor{red}{3}\right)}^{3} - \left(7 \times \textcolor{red}{3}\right) = 27 - 21 = 6$