(X+2)(x)=9x+30

Solution for (X+2)(x)=9x+30 equation:

(X+2)(X)=9X+30

We move all terms to the left:

(X+2)(X)-(9X+30)=0

We multiply parentheses

X^2+2X-(9X+30)=0

We get rid of parentheses

X^2+2X-9X-30=0

We add all the numbers together, and all the variables

X^2-7X-30=0

a = 1; b = -7; c = -30;
Δ = b2-4ac
Δ = -72-4·1·(-30)
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-13}{2*1}=\frac{-6}{2}
=-3
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+13}{2*1}=\frac{20}{2}
=10
$