28=(5+x)2x

Solution for 28=(5+x)2x equation:

28=(5+x)2x

We move all terms to the left:

28-((5+x)2x)=0

We add all the numbers together, and all the variables

-((x+5)2x)+28=0


We calculate terms in parentheses: -((x+5)2x), so:

(x+5)2x

We multiply parentheses

2x^2+10x

Back to the equation:

-(2x^2+10x)


We get rid of parentheses

-2x^2-10x+28=0

a = -2; b = -10; c = +28;
Δ = b2-4ac
Δ = -102-4·(-2)·28
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-18}{2*-2}=\frac{-8}{-4}
=+2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+18}{2*-2}=\frac{28}{-4}
=-7
$