-4.9t2+43.4t+6.3=0

Solution for -4.9t2+43.4t+6.3=0 equation:

-4.9t^2+43.4t+6.3=0

a = -4.9; b = 43.4; c = +6.3;
Δ = b2-4ac
Δ = 43.42-4·(-4.9)·6.3
Δ = 2007.04
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(43.4)-\sqrt{2007.04}}{2*-4.9}=\frac{-43.4-\sqrt{2007.04}}{-9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(43.4)+\sqrt{2007.04}}{2*-4.9}=\frac{-43.4+\sqrt{2007.04}}{-9.8}
$