180=7x-3x(-6x+15)

Solution for 180=7x-3x(-6x+15) equation:

180=7x-3x(-6x+15)

We move all terms to the left:

180-(7x-3x(-6x+15))=0


We calculate terms in parentheses: -(7x-3x(-6x+15)), so:

7x-3x(-6x+15)

We multiply parentheses

18x^2+7x-45x

We add all the numbers together, and all the variables

18x^2-38x

Back to the equation:

-(18x^2-38x)


We get rid of parentheses

-18x^2+38x+180=0

a = -18; b = 38; c = +180;
Δ = b2-4ac
Δ = 382-4·(-18)·180
Δ = 14404
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:

$\sqrt{\Delta}=\sqrt{14404}=\sqrt{4*3601}=\sqrt{4}*\sqrt{3601}=2\sqrt{3601}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(38)-2\sqrt{3601}}{2*-18}=\frac{-38-2\sqrt{3601}}{-36}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(38)+2\sqrt{3601}}{2*-18}=\frac{-38+2\sqrt{3601}}{-36}
$