(10x-7)(-2x+4)=0

Solution for (10x-7)(-2x+4)=0 equation:

(10x-7)(-2x+4)=0

We multiply parentheses ..

(-20x^2+40x+14x-28)=0

We get rid of parentheses

-20x^2+40x+14x-28=0

We add all the numbers together, and all the variables

-20x^2+54x-28=0

a = -20; b = 54; c = -28;
Δ = b2-4ac
Δ = 542-4·(-20)·(-28)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(54)-26}{2*-20}=\frac{-80}{-40}
=+2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(54)+26}{2*-20}=\frac{-28}{-40}
=7/10
$