(2x-5)(8x+6)=0

Solution for (2x-5)(8x+6)=0 equation:

(2x-5)(8x+6)=0

We multiply parentheses ..

(+16x^2+12x-40x-30)=0

We get rid of parentheses

16x^2+12x-40x-30=0

We add all the numbers together, and all the variables

16x^2-28x-30=0

a = 16; b = -28; c = -30;
Δ = b2-4ac
Δ = -282-4·16·(-30)
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-28)-52}{2*16}=\frac{-24}{32}
=-3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+52}{2*16}=\frac{80}{32}
=2+1/2
$