4.9t^2-5t-760=0

Solution for 4.9t^2-5t-760=0 equation:

4.9t^2-5t-760=0

a = 4.9; b = -5; c = -760;
Δ = b2-4ac
Δ = -52-4·4.9·(-760)
Δ = 14921
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{14921}=\sqrt{1*14921}=\sqrt{1}*\sqrt{14921}=1\sqrt{14921}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-1\sqrt{14921}}{2*4.9}=\frac{5-1\sqrt{14921}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+1\sqrt{14921}}{2*4.9}=\frac{5+1\sqrt{14921}}{9.8}
$