(X+3)=3x^2+3x-90

Solution for (X+3)=3x^2+3x-90 equation:

(X+3)=3X^2+3X-90

We move all terms to the left:

(X+3)-(3X^2+3X-90)=0

We get rid of parentheses

-3X^2+X-3X+3+90=0

We add all the numbers together, and all the variables

-3X^2-2X+93=0

a = -3; b = -2; c = +93;
Δ = b2-4ac
Δ = -22-4·(-3)·93
Δ = 1120
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1120}=\sqrt{16*70}=\sqrt{16}*\sqrt{70}=4\sqrt{70}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-4\sqrt{70}}{2*-3}=\frac{2-4\sqrt{70}}{-6}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+4\sqrt{70}}{2*-3}=\frac{2+4\sqrt{70}}{-6}
$