-4.9x^2-14x+100=0

Solution for -4.9x^2-14x+100=0 equation:

-4.9x^2-14x+100=0

a = -4.9; b = -14; c = +100;
Δ = b2-4ac
Δ = -142-4·(-4.9)·100
Δ = 2156
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:

$\sqrt{\Delta}=\sqrt{2156}=\sqrt{196*11}=\sqrt{196}*\sqrt{11}=14\sqrt{11}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-14\sqrt{11}}{2*-4.9}=\frac{14-14\sqrt{11}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+14\sqrt{11}}{2*-4.9}=\frac{14+14\sqrt{11}}{-9.8}
$