4.9x^2-14x-40=0

Solution for 4.9x^2-14x-40=0 equation:

4.9x^2-14x-40=0

a = 4.9; b = -14; c = -40;
Δ = b2-4ac
Δ = -142-4·4.9·(-40)
Δ = 980
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:

$\sqrt{\Delta}=\sqrt{980}=\sqrt{196*5}=\sqrt{196}*\sqrt{5}=14\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-14\sqrt{5}}{2*4.9}=\frac{14-14\sqrt{5}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+14\sqrt{5}}{2*4.9}=\frac{14+14\sqrt{5}}{9.8}
$