(x+3)(x+5)=195

Solution for (x+3)(x+5)=195 equation:

(x+3)(x+5)=195

We move all terms to the left:

(x+3)(x+5)-(195)=0

We multiply parentheses ..

(+x^2+5x+3x+15)-195=0

We get rid of parentheses

x^2+5x+3x+15-195=0

We add all the numbers together, and all the variables

x^2+8x-180=0

a = 1; b = 8; c = -180;
Δ = b2-4ac
Δ = 82-4·1·(-180)
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-28}{2*1}=\frac{-36}{2}
=-18
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+28}{2*1}=\frac{20}{2}
=10
$