3x^2=-72+30x

Solution for 3x^2=-72+30x equation:

3x^2=-72+30x

We move all terms to the left:

3x^2-(-72+30x)=0

We add all the numbers together, and all the variables

3x^2-(30x-72)=0

We get rid of parentheses

3x^2-30x+72=0

a = 3; b = -30; c = +72;
Δ = b2-4ac
Δ = -302-4·3·72
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-6}{2*3}=\frac{24}{6}
=4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+6}{2*3}=\frac{36}{6}
=6
$