(5x-1)(14x+28)=0

Solution for (5x-1)(14x+28)=0 equation:

(5x-1)(14x+28)=0

We multiply parentheses ..

(+70x^2+140x-14x-28)=0

We get rid of parentheses

70x^2+140x-14x-28=0

We add all the numbers together, and all the variables

70x^2+126x-28=0

a = 70; b = 126; c = -28;
Δ = b2-4ac
Δ = 1262-4·70·(-28)
Δ = 23716
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{23716}=154$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(126)-154}{2*70}=\frac{-280}{140}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(126)+154}{2*70}=\frac{28}{140}
=1/5
$