(X-8)(2x-8)=154

Solution for (X-8)(2x-8)=154 equation:

(X-8)(2X-8)=154

We move all terms to the left:

(X-8)(2X-8)-(154)=0

We multiply parentheses ..

(+2X^2-8X-16X+64)-154=0

We get rid of parentheses

2X^2-8X-16X+64-154=0

We add all the numbers together, and all the variables

2X^2-24X-90=0

a = 2; b = -24; c = -90;
Δ = b2-4ac
Δ = -242-4·2·(-90)
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-24)-36}{2*2}=\frac{-12}{4}
=-3
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-24)+36}{2*2}=\frac{60}{4}
=15
$