x+15+2x+20=2x^2

Solution for x+15+2x+20=2x^2 equation:

x+15+2x+20=2x^2

We move all terms to the left:

x+15+2x+20-(2x^2)=0

determiningTheFunctionDomain
-2x^2+x+2x+15+20=0

We add all the numbers together, and all the variables

-2x^2+3x+35=0

a = -2; b = 3; c = +35;
Δ = b2-4ac
Δ = 32-4·(-2)·35
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-17}{2*-2}=\frac{-20}{-4}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+17}{2*-2}=\frac{14}{-4}
=-3+1/2
$