1350=(x+15)(x)

Solution for 1350=(x+15)(x) equation:

1350=(x+15)(x)

We move all terms to the left:

1350-((x+15)(x))=0


We calculate terms in parentheses: -((x+15)x), so:

(x+15)x

We multiply parentheses

x^2+15x

Back to the equation:

-(x^2+15x)


We get rid of parentheses

-x^2-15x+1350=0

We add all the numbers together, and all the variables

-1x^2-15x+1350=0

a = -1; b = -15; c = +1350;
Δ = b2-4ac
Δ = -152-4·(-1)·1350
Δ = 5625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5625}=75$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-75}{2*-1}=\frac{-60}{-2}
=+30
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+75}{2*-1}=\frac{90}{-2}
=-45
$