-2x(7x+15)=18+2x

Solution for -2x(7x+15)=18+2x equation:

-2x(7x+15)=18+2x

We move all terms to the left:

-2x(7x+15)-(18+2x)=0

We add all the numbers together, and all the variables

-2x(7x+15)-(2x+18)=0

We multiply parentheses

-14x^2-30x-(2x+18)=0

We get rid of parentheses

-14x^2-30x-2x-18=0

We add all the numbers together, and all the variables

-14x^2-32x-18=0

a = -14; b = -32; c = -18;
Δ = b2-4ac
Δ = -322-4·(-14)·(-18)
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-32)-4}{2*-14}=\frac{28}{-28}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-32)+4}{2*-14}=\frac{36}{-28}
=-1+2/7
$