(x+18)(5x-30)=

Solution for (x+18)(5x-30)= equation:

(x+18)(5x-30)=

We move all terms to the left:

(x+18)(5x-30)-()=0

We add all the numbers together, and all the variables

(x+18)(5x-30)=0

We multiply parentheses ..

(+5x^2-30x+90x-540)=0

We get rid of parentheses

5x^2-30x+90x-540=0

We add all the numbers together, and all the variables

5x^2+60x-540=0

a = 5; b = 60; c = -540;
Δ = b2-4ac
Δ = 602-4·5·(-540)
Δ = 14400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14400}=120$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(60)-120}{2*5}=\frac{-180}{10}
=-18
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(60)+120}{2*5}=\frac{60}{10}
=6
$