2x(x-+3)=2x*2+15

Solution for 2x(x-+3)=2x*2+15 equation:

2x(x-+3)=2x*2+15

We move all terms to the left:

2x(x-+3)-(2x*2+15)=0

We add all the numbers together, and all the variables

2x(+x)-(2x*2+15)=0

We multiply parentheses

2x^2-(2x*2+15)=0

We get rid of parentheses

2x^2-2x*2-15=0

Wy multiply elements

2x^2-4x-15=0

a = 2; b = -4; c = -15;
Δ = b2-4ac
Δ = -42-4·2·(-15)
Δ = 136
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:

$\sqrt{\Delta}=\sqrt{136}=\sqrt{4*34}=\sqrt{4}*\sqrt{34}=2\sqrt{34}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-2\sqrt{34}}{2*2}=\frac{4-2\sqrt{34}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+2\sqrt{34}}{2*2}=\frac{4+2\sqrt{34}}{4}
$