4.9t^2-17.16t-13=0

Solution for 4.9t^2-17.16t-13=0 equation:

4.9t^2-17.16t-13=0

a = 4.9; b = -17.16; c = -13;
Δ = b2-4ac
Δ = -17.162-4·4.9·(-13)
Δ = 549.2656
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{-(-17.16)-\sqrt{549.2656}}{2*4.9}=\frac{17.16-\sqrt{549.2656}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-17.16)+\sqrt{549.2656}}{2*4.9}=\frac{17.16+\sqrt{549.2656}}{9.8}
$