4.9t^2-15t-40t=0

Solution for 4.9t^2-15t-40t=0 equation:

4.9t^2-15t-40t=0

We add all the numbers together, and all the variables

4.9t^2-55t=0

a = 4.9; b = -55; c = 0;
Δ = b2-4ac
Δ = -552-4·4.9·0
Δ = 3025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3025}=55$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-55)-55}{2*4.9}=\frac{0}{9.8}
=0
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-55)+55}{2*4.9}=\frac{110}{9.8}
=11+2.2/9.8
$