4.9x^2+9x-1.2=0

Solution for 4.9x^2+9x-1.2=0 equation:

4.9x^2+9x-1.2=0

a = 4.9; b = 9; c = -1.2;
Δ = b2-4ac
Δ = 92-4·4.9·(-1.2)
Δ = 104.52
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-\sqrt{104.52}}{2*4.9}=\frac{-9-\sqrt{104.52}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{104.52}}{2*4.9}=\frac{-9+\sqrt{104.52}}{9.8}
$