4x^2-21x-324=0

Solution for 4x^2-21x-324=0 equation:

4x^2-21x-324=0

a = 4; b = -21; c = -324;
Δ = b2-4ac
Δ = -212-4·4·(-324)
Δ = 5625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5625}=75$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-21)-75}{2*4}=\frac{-54}{8}
=-6+3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-21)+75}{2*4}=\frac{96}{8}
=12
$