2x(4x-5)=88

Solution for 2x(4x-5)=88 equation:

2x(4x-5)=88

We move all terms to the left:

2x(4x-5)-(88)=0

We multiply parentheses

8x^2-10x-88=0

a = 8; b = -10; c = -88;
Δ = b2-4ac
Δ = -102-4·8·(-88)
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-54}{2*8}=\frac{-44}{16}
=-2+3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+54}{2*8}=\frac{64}{16}
=4
$