(-16x^2-50x+42)=0

Solution for (-16x^2-50x+42)=0 equation:

(-16x^2-50x+42)=0

We get rid of parentheses

-16x^2-50x+42=0

a = -16; b = -50; c = +42;
Δ = b2-4ac
Δ = -502-4·(-16)·42
Δ = 5188
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:

$\sqrt{\Delta}=\sqrt{5188}=\sqrt{4*1297}=\sqrt{4}*\sqrt{1297}=2\sqrt{1297}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-50)-2\sqrt{1297}}{2*-16}=\frac{50-2\sqrt{1297}}{-32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-50)+2\sqrt{1297}}{2*-16}=\frac{50+2\sqrt{1297}}{-32}
$