(x+3)(x-4)=5

Solution for (x+3)(x-4)=5 equation:

(x+3)(x-4)=5

We move all terms to the left:

(x+3)(x-4)-(5)=0

We multiply parentheses ..

(+x^2-4x+3x-12)-5=0

We get rid of parentheses

x^2-4x+3x-12-5=0

We add all the numbers together, and all the variables

x^2-1x-17=0

a = 1; b = -1; c = -17;
Δ = b2-4ac
Δ = -12-4·1·(-17)
Δ = 69
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{-(-1)-\sqrt{69}}{2*1}=\frac{1-\sqrt{69}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{69}}{2*1}=\frac{1+\sqrt{69}}{2}
$