(4-2x)(7-2x)=88

Solution for (4-2x)(7-2x)=88 equation:

(4-2x)(7-2x)=88

We move all terms to the left:

(4-2x)(7-2x)-(88)=0

We add all the numbers together, and all the variables

(-2x+4)(-2x+7)-88=0

We multiply parentheses ..

(+4x^2-14x-8x+28)-88=0

We get rid of parentheses

4x^2-14x-8x+28-88=0

We add all the numbers together, and all the variables

4x^2-22x-60=0

a = 4; b = -22; c = -60;
Δ = b2-4ac
Δ = -222-4·4·(-60)
Δ = 1444
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1444}=38$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-22)-38}{2*4}=\frac{-16}{8}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-22)+38}{2*4}=\frac{60}{8}
=7+1/2
$