-1(x)=2x^2+5x-17

Solution for -1(x)=2x^2+5x-17 equation:

-1(x)=2x^2+5x-17

We move all terms to the left:

-1(x)-(2x^2+5x-17)=0

We get rid of parentheses

-2x^2-1x-5x+17=0

We add all the numbers together, and all the variables

-2x^2-6x+17=0

a = -2; b = -6; c = +17;
Δ = b2-4ac
Δ = -62-4·(-2)·17
Δ = 172
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{172}=\sqrt{4*43}=\sqrt{4}*\sqrt{43}=2\sqrt{43}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-2\sqrt{43}}{2*-2}=\frac{6-2\sqrt{43}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+2\sqrt{43}}{2*-2}=\frac{6+2\sqrt{43}}{-4}
$