72.25=x^2+8.8x

Solution for 72.25=x^2+8.8x equation:

72.25=x^2+8.8x

We move all terms to the left:

72.25-(x^2+8.8x)=0

We get rid of parentheses

-x^2-8.8x+72.25=0

We add all the numbers together, and all the variables

-1x^2-8.8x+72.25=0

a = -1; b = -8.8; c = +72.25;
Δ = b2-4ac
Δ = -8.82-4·(-1)·72.25
Δ = 366.44
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{-(-8.8)-\sqrt{366.44}}{2*-1}=\frac{8.8-\sqrt{366.44}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8.8)+\sqrt{366.44}}{2*-1}=\frac{8.8+\sqrt{366.44}}{-2}
$