5x^2+5x-18-342=0

Solution for 5x^2+5x-18-342=0 equation:

5x^2+5x-18-342=0

We add all the numbers together, and all the variables

5x^2+5x-360=0

a = 5; b = 5; c = -360;
Δ = b2-4ac
Δ = 52-4·5·(-360)
Δ = 7225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7225}=85$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-85}{2*5}=\frac{-90}{10}
=-9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+85}{2*5}=\frac{80}{10}
=8
$