100=9x^2

Solution for 100=9x^2 equation:

100=9x^2

We move all terms to the left:

100-(9x^2)=0

a = -9; b = 0; c = +100;
Δ = b2-4ac
Δ = 02-4·(-9)·100
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-60}{2*-9}=\frac{-60}{-18}
=3+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+60}{2*-9}=\frac{60}{-18}
=-3+1/3
$