729=x^2+.5625x^2

Solution for 729=x^2+.5625x^2 equation:

729=x^2+.5625x^2

We move all terms to the left:

729-(x^2+.5625x^2)=0

We get rid of parentheses

-x^2-.5625x^2+729=0

We add all the numbers together, and all the variables

-1.5625x^2+729=0

a = -1.5625; b = 0; c = +729;
Δ = b2-4ac
Δ = 02-4·(-1.5625)·729
Δ = 4556.25
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)-\sqrt{4556.25}}{2*-1.5625}=\frac{0-\sqrt{4556.25}}{-3.125}
=-\frac{\sqrt{}}{-3.125}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{4556.25}}{2*-1.5625}=\frac{0+\sqrt{4556.25}}{-3.125}
=\frac{\sqrt{}}{-3.125}
$