4x^2+24x-42=0

Solution for 4x^2+24x-42=0 equation:

4x^2+24x-42=0

a = 4; b = 24; c = -42;
Δ = b2-4ac
Δ = 242-4·4·(-42)
Δ = 1248
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1248}=\sqrt{16*78}=\sqrt{16}*\sqrt{78}=4\sqrt{78}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(24)-4\sqrt{78}}{2*4}=\frac{-24-4\sqrt{78}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(24)+4\sqrt{78}}{2*4}=\frac{-24+4\sqrt{78}}{8}
$