-1(x)=6x^2-4

Solution for -1(x)=6x^2-4 equation:

-1(x)=6x^2-4

We move all terms to the left:

-1(x)-(6x^2-4)=0

We get rid of parentheses

-6x^2-1x+4=0

a = -6; b = -1; c = +4;
Δ = b2-4ac
Δ = -12-4·(-6)·4
Δ = 97
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{97}}{2*-6}=\frac{1-\sqrt{97}}{-12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{97}}{2*-6}=\frac{1+\sqrt{97}}{-12}
$