2x(80+x)=4x+1.5(90)

Solution for 2x(80+x)=4x+1.5(90) equation:

2x(80+x)=4x+1.5(90)

We move all terms to the left:

2x(80+x)-(4x+1.5(90))=0

We add all the numbers together, and all the variables

2x(x+80)-(4x+1.59)=0

We multiply parentheses

2x^2+160x-(4x+1.59)=0

We get rid of parentheses

2x^2+160x-4x-1.59=0

We add all the numbers together, and all the variables

2x^2+156x-1.59=0

a = 2; b = 156; c = -1.59;
Δ = b2-4ac
Δ = 1562-4·2·(-1.59)
Δ = 24348.72
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(156)-\sqrt{24348.72}}{2*2}=\frac{-156-\sqrt{24348.72}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(156)+\sqrt{24348.72}}{2*2}=\frac{-156+\sqrt{24348.72}}{4}
$