(2x+10)(2x-7)=0

Solution for (2x+10)(2x-7)=0 equation:

(2x+10)(2x-7)=0

We multiply parentheses ..

(+4x^2-14x+20x-70)=0

We get rid of parentheses

4x^2-14x+20x-70=0

We add all the numbers together, and all the variables

4x^2+6x-70=0

a = 4; b = 6; c = -70;
Δ = b2-4ac
Δ = 62-4·4·(-70)
Δ = 1156
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1156}=34$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-34}{2*4}=\frac{-40}{8}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+34}{2*4}=\frac{28}{8}
=3+1/2
$