0.20x+0.25x(x+40)=0.35(x+80)

Solution for 0.20x+0.25x(x+40)=0.35(x+80) equation:

0.20x+0.25x(x+40)=0.35(x+80)

We move all terms to the left:

0.20x+0.25x(x+40)-(0.35(x+80))=0

We multiply parentheses

0x^2+0.20x+0x-(0.35(x+80))=0


We calculate terms in parentheses: -(0.35(x+80)), so:

0.35(x+80)

We multiply parentheses

0.35x+28

Back to the equation:

-(0.35x+28)


We add all the numbers together, and all the variables

x^2+1.2x-(0.35x+28)=0

We get rid of parentheses

x^2+1.2x-0.35x-28=0

We add all the numbers together, and all the variables

x^2+0.85x-28=0

a = 1; b = 0.85; c = -28;
Δ = b2-4ac
Δ = 0.852-4·1·(-28)
Δ = 112.7225
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{-(0.85)-\sqrt{112.7225}}{2*1}=\frac{-0.85-\sqrt{112.7225}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.85)+\sqrt{112.7225}}{2*1}=\frac{-0.85+\sqrt{112.7225}}{2}
$