(X-1)(x-3)=48

Solution for (X-1)(x-3)=48 equation:

(X-1)(X-3)=48

We move all terms to the left:

(X-1)(X-3)-(48)=0

We multiply parentheses ..

(+X^2-3X-1X+3)-48=0

We get rid of parentheses

X^2-3X-1X+3-48=0

We add all the numbers together, and all the variables

X^2-4X-45=0

a = 1; b = -4; c = -45;
Δ = b2-4ac
Δ = -42-4·1·(-45)
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-14}{2*1}=\frac{-10}{2}
=-5
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+14}{2*1}=\frac{18}{2}
=9
$