21x2-5x-50=0

Solution for 21x2-5x-50=0 equation:

21x^2-5x-50=0

a = 21; b = -5; c = -50;
Δ = b2-4ac
Δ = -52-4·21·(-50)
Δ = 4225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4225}=65$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-65}{2*21}=\frac{-60}{42}
=-1+3/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+65}{2*21}=\frac{70}{42}
=1+2/3
$