21m^2+17m-30=0

Solution for 21m^2+17m-30=0 equation:

21m^2+17m-30=0

a = 21; b = 17; c = -30;
Δ = b2-4ac
Δ = 172-4·21·(-30)
Δ = 2809
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2809}=53$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(17)-53}{2*21}=\frac{-70}{42}
=-1+2/3
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(17)+53}{2*21}=\frac{36}{42}
=6/7
$