360=5x(4x+45)

Solution for 360=5x(4x+45) equation:

360=5x(4x+45)

We move all terms to the left:

360-(5x(4x+45))=0


We calculate terms in parentheses: -(5x(4x+45)), so:

5x(4x+45)

We multiply parentheses

20x^2+225x

Back to the equation:

-(20x^2+225x)


We get rid of parentheses

-20x^2-225x+360=0

a = -20; b = -225; c = +360;
Δ = b2-4ac
Δ = -2252-4·(-20)·360
Δ = 79425
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{79425}=\sqrt{225*353}=\sqrt{225}*\sqrt{353}=15\sqrt{353}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-225)-15\sqrt{353}}{2*-20}=\frac{225-15\sqrt{353}}{-40}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-225)+15\sqrt{353}}{2*-20}=\frac{225+15\sqrt{353}}{-40}
$