.9x^2=2500

Solution for .9x^2=2500 equation:

.9x^2=2500

We move all terms to the left:

.9x^2-(2500)=0

a = .9; b = 0; c = -2500;
Δ = b2-4ac
Δ = 02-4·.9·(-2500)
Δ = 9000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{9000}=\sqrt{900*10}=\sqrt{900}*\sqrt{10}=30\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-30\sqrt{10}}{2*.9}=\frac{0-30\sqrt{10}}{1.8}
=-\frac{30\sqrt{10}}{1.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+30\sqrt{10}}{2*.9}=\frac{0+30\sqrt{10}}{1.8}
=\frac{30\sqrt{10}}{1.8}
$