7500=3a*a

Solution for 7500=3a*a equation:

7500=3a*a

We move all terms to the left:

7500-(3a*a)=0

We add all the numbers together, and all the variables

-(+3a*a)+7500=0

We get rid of parentheses

-3a*a+7500=0

Wy multiply elements

-3a^2+7500=0

a = -3; b = 0; c = +7500;
Δ = b2-4ac
Δ = 02-4·(-3)·7500
Δ = 90000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{90000}=300$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-300}{2*-3}=\frac{-300}{-6}
=+50
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+300}{2*-3}=\frac{300}{-6}
=-50
$