3a^2+17a-90=0

Solution for 3a^2+17a-90=0 equation:

3a^2+17a-90=0

a = 3; b = 17; c = -90;
Δ = b2-4ac
Δ = 172-4·3·(-90)
Δ = 1369
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1369}=37$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(17)-37}{2*3}=\frac{-54}{6}
=-9
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(17)+37}{2*3}=\frac{20}{6}
=3+1/3
$