21a^2-38a-48=0

Solution for 21a^2-38a-48=0 equation:

21a^2-38a-48=0

a = 21; b = -38; c = -48;
Δ = b2-4ac
Δ = -382-4·21·(-48)
Δ = 5476
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5476}=74$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-38)-74}{2*21}=\frac{-36}{42}
=-6/7
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-38)+74}{2*21}=\frac{112}{42}
=2+2/3
$