(2x-14)(x+5)=0

Solution for (2x-14)(x+5)=0 equation:

(2x-14)(x+5)=0

We multiply parentheses ..

(+2x^2+10x-14x-70)=0

We get rid of parentheses

2x^2+10x-14x-70=0

We add all the numbers together, and all the variables

2x^2-4x-70=0

a = 2; b = -4; c = -70;
Δ = b2-4ac
Δ = -42-4·2·(-70)
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-24}{2*2}=\frac{-20}{4}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+24}{2*2}=\frac{28}{4}
=7
$