6.25=2x+x^2

Solution for 6.25=2x+x^2 equation:

6.25=2x+x^2

We move all terms to the left:

6.25-(2x+x^2)=0

We get rid of parentheses

-x^2-2x+6.25=0

We add all the numbers together, and all the variables

-1x^2-2x+6.25=0

a = -1; b = -2; c = +6.25;
Δ = b2-4ac
Δ = -22-4·(-1)·6.25
Δ = 29
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{-(-2)-\sqrt{29}}{2*-1}=\frac{2-\sqrt{29}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+\sqrt{29}}{2*-1}=\frac{2+\sqrt{29}}{-2}
$