5a*9a=45a

Solution for 5a*9a=45a equation:

5a*9a=45a

We move all terms to the left:

5a*9a-(45a)=0

We add all the numbers together, and all the variables

-45a+5a*9a=0

Wy multiply elements

45a^2-45a=0

a = 45; b = -45; c = 0;
Δ = b2-4ac
Δ = -452-4·45·0
Δ = 2025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2025}=45$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-45)-45}{2*45}=\frac{0}{90}
=0
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-45)+45}{2*45}=\frac{90}{90}
=1
$