9a(9=15a)=100

Solution for 9a(9=15a)=100 equation:

9a(9=15a)=100

We move all terms to the left:

9a(9-(15a))=0

We add all the numbers together, and all the variables

9a(-15a+9)=0

We multiply parentheses

-135a^2+81a=0

a = -135; b = 81; c = 0;
Δ = b2-4ac
Δ = 812-4·(-135)·0
Δ = 6561
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6561}=81$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(81)-81}{2*-135}=\frac{-162}{-270}
=3/5
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(81)+81}{2*-135}=\frac{0}{-270}
=0
$