3m^2-90=-3m

Solution for 3m^2-90=-3m equation:

3m^2-90=-3m

We move all terms to the left:

3m^2-90-(-3m)=0

We get rid of parentheses

3m^2+3m-90=0

a = 3; b = 3; c = -90;
Δ = b2-4ac
Δ = 32-4·3·(-90)
Δ = 1089
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1089}=33$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-33}{2*3}=\frac{-36}{6}
=-6
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+33}{2*3}=\frac{30}{6}
=5
$