G(-x)=-3x^2+2x+16

Solution for G(-x)=-3x^2+2x+16 equation:

(-G)=-3G^2+2G+16

We move all terms to the left:

(-G)-(-3G^2+2G+16)=0

We add all the numbers together, and all the variables

-(-3G^2+2G+16)+(-1G)=0

We get rid of parentheses

3G^2-2G-1G-16=0

We add all the numbers together, and all the variables

3G^2-3G-16=0

a = 3; b = -3; c = -16;
Δ = b2-4ac
Δ = -32-4·3·(-16)
Δ = 201
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$G_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$G_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$G_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-\sqrt{201}}{2*3}=\frac{3-\sqrt{201}}{6}
$
$G_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+\sqrt{201}}{2*3}=\frac{3+\sqrt{201}}{6}
$