(x-2)(x+0.8)=32

Solution for (x-2)(x+0.8)=32 equation:

(x-2)(x+0.8)=32

We move all terms to the left:

(x-2)(x+0.8)-(32)=0

We multiply parentheses ..

(+x^2+0.8x-2x-1.6)-32=0

We get rid of parentheses

x^2+0.8x-2x-1.6-32=0

We add all the numbers together, and all the variables

x^2-1.2x-33.6=0

a = 1; b = -1.2; c = -33.6;
Δ = b2-4ac
Δ = -1.22-4·1·(-33.6)
Δ = 135.84
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1.2)-\sqrt{135.84}}{2*1}=\frac{1.2-\sqrt{135.84}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.2)+\sqrt{135.84}}{2*1}=\frac{1.2+\sqrt{135.84}}{2}
$