(x+2)(8x-2)=180

Solution for (x+2)(8x-2)=180 equation:

(x+2)(8x-2)=180

We move all terms to the left:

(x+2)(8x-2)-(180)=0

We multiply parentheses ..

(+8x^2-2x+16x-4)-180=0

We get rid of parentheses

8x^2-2x+16x-4-180=0

We add all the numbers together, and all the variables

8x^2+14x-184=0

a = 8; b = 14; c = -184;
Δ = b2-4ac
Δ = 142-4·8·(-184)
Δ = 6084
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6084}=78$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-78}{2*8}=\frac{-92}{16}
=-5+3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+78}{2*8}=\frac{64}{16}
=4
$