(X-1)(x+6)=144

Solution for (X-1)(x+6)=144 equation:

(X-1)(X+6)=144

We move all terms to the left:

(X-1)(X+6)-(144)=0

We multiply parentheses ..

(+X^2+6X-1X-6)-144=0

We get rid of parentheses

X^2+6X-1X-6-144=0

We add all the numbers together, and all the variables

X^2+5X-150=0

a = 1; b = 5; c = -150;
Δ = b2-4ac
Δ = 52-4·1·(-150)
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-25}{2*1}=\frac{-30}{2}
=-15
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+25}{2*1}=\frac{20}{2}
=10
$