3x^2+5x+9+3x+1=90

Solution for 3x^2+5x+9+3x+1=90 equation:

3x^2+5x+9+3x+1=90

We move all terms to the left:

3x^2+5x+9+3x+1-(90)=0

We add all the numbers together, and all the variables

3x^2+8x-80=0

a = 3; b = 8; c = -80;
Δ = b2-4ac
Δ = 82-4·3·(-80)
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-32}{2*3}=\frac{-40}{6}
=-6+2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+32}{2*3}=\frac{24}{6}
=4
$