X2-7x=144

Solution for X2-7x=144 equation:

X2-7X=144

We move all terms to the left:

X2-7X-(144)=0

We add all the numbers together, and all the variables

X^2-7X-144=0

a = 1; b = -7; c = -144;
Δ = b2-4ac
Δ = -72-4·1·(-144)
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{-(-7)-25}{2*1}=\frac{-18}{2}
=-9
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+25}{2*1}=\frac{32}{2}
=16
$