(X+2)(x-2)+3x=35

Solution for (X+2)(x-2)+3x=35 equation:

(X+2)(X-2)+3X=35

We move all terms to the left:

(X+2)(X-2)+3X-(35)=0

We add all the numbers together, and all the variables

3X+(X+2)(X-2)-35=0

We use the square of the difference formula

X^2+3X-4-35=0

We add all the numbers together, and all the variables

X^2+3X-39=0

a = 1; b = 3; c = -39;
Δ = b2-4ac
Δ = 32-4·1·(-39)
Δ = 165
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{-(3)-\sqrt{165}}{2*1}=\frac{-3-\sqrt{165}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{165}}{2*1}=\frac{-3+\sqrt{165}}{2}
$