(x-4)(x-1)=24

Solution for (x-4)(x-1)=24 equation:

(x-4)(x-1)=24

We move all terms to the left:

(x-4)(x-1)-(24)=0

We multiply parentheses ..

(+x^2-1x-4x+4)-24=0

We get rid of parentheses

x^2-1x-4x+4-24=0

We add all the numbers together, and all the variables

x^2-5x-20=0

a = 1; b = -5; c = -20;
Δ = b2-4ac
Δ = -52-4·1·(-20)
Δ = 105
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{-(-5)-\sqrt{105}}{2*1}=\frac{5-\sqrt{105}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+\sqrt{105}}{2*1}=\frac{5+\sqrt{105}}{2}
$