-14x^2+30x+4=0

Solution for -14x^2+30x+4=0 equation:

-14x^2+30x+4=0

a = -14; b = 30; c = +4;
Δ = b2-4ac
Δ = 302-4·(-14)·4
Δ = 1124
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:

$\sqrt{\Delta}=\sqrt{1124}=\sqrt{4*281}=\sqrt{4}*\sqrt{281}=2\sqrt{281}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-2\sqrt{281}}{2*-14}=\frac{-30-2\sqrt{281}}{-28}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+2\sqrt{281}}{2*-14}=\frac{-30+2\sqrt{281}}{-28}
$