-49x^2-56x+16=0

Solution for -49x^2-56x+16=0 equation:

-49x^2-56x+16=0

a = -49; b = -56; c = +16;
Δ = b2-4ac
Δ = -562-4·(-49)·16
Δ = 6272
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:

$\sqrt{\Delta}=\sqrt{6272}=\sqrt{3136*2}=\sqrt{3136}*\sqrt{2}=56\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-56\sqrt{2}}{2*-49}=\frac{56-56\sqrt{2}}{-98}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+56\sqrt{2}}{2*-49}=\frac{56+56\sqrt{2}}{-98}
$