# How do you evaluate the function f(x)=6x^2+2x-12 for f(-x)?

$f \left(- x\right) = 6 {x}^{2} - 2 x - 12$
$\text{substitute "x=-x" into } f \left(x\right)$
$f \left(\textcolor{red}{- x}\right) = 6 {\left(\textcolor{red}{- x}\right)}^{2} + 2 \left(\textcolor{red}{- x}\right) - 12$
$\textcolor{w h i t e}{\times \times x} = 6 {x}^{2} - 2 x - 12$