9x+80=8x(x+10)

Solution for 9x+80=8x(x+10) equation:

9x+80=8x(x+10)

We move all terms to the left:

9x+80-(8x(x+10))=0


We calculate terms in parentheses: -(8x(x+10)), so:

8x(x+10)

We multiply parentheses

8x^2+80x

Back to the equation:

-(8x^2+80x)


We get rid of parentheses

-8x^2+9x-80x+80=0

We add all the numbers together, and all the variables

-8x^2-71x+80=0

a = -8; b = -71; c = +80;
Δ = b2-4ac
Δ = -712-4·(-8)·80
Δ = 7601
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{-(-71)-\sqrt{7601}}{2*-8}=\frac{71-\sqrt{7601}}{-16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-71)+\sqrt{7601}}{2*-8}=\frac{71+\sqrt{7601}}{-16}
$