21x^2+3x=24

Solution for 21x^2+3x=24 equation:

21x^2+3x=24

We move all terms to the left:

21x^2+3x-(24)=0

a = 21; b = 3; c = -24;
Δ = b2-4ac
Δ = 32-4·21·(-24)
Δ = 2025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2025}=45$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-45}{2*21}=\frac{-48}{42}
=-1+1/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+45}{2*21}=\frac{42}{42}
=1
$