0=-2(8x^2-5x-90)

Solution for 0=-2(8x^2-5x-90) equation:

0=-2(8x^2-5x-90)

We move all terms to the left:

0-(-2(8x^2-5x-90))=0

We add all the numbers together, and all the variables

-(-2(8x^2-5x-90))=0


We calculate terms in parentheses: -(-2(8x^2-5x-90)), so:

-2(8x^2-5x-90)

We multiply parentheses

-16x^2+10x+180

Back to the equation:

-(-16x^2+10x+180)


We get rid of parentheses

16x^2-10x-180=0

a = 16; b = -10; c = -180;
Δ = b2-4ac
Δ = -102-4·16·(-180)
Δ = 11620
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:

$\sqrt{\Delta}=\sqrt{11620}=\sqrt{4*2905}=\sqrt{4}*\sqrt{2905}=2\sqrt{2905}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-2\sqrt{2905}}{2*16}=\frac{10-2\sqrt{2905}}{32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+2\sqrt{2905}}{2*16}=\frac{10+2\sqrt{2905}}{32}
$