4.73=-4.9t^2+40t+100

Solution for 4.73=-4.9t^2+40t+100 equation:

4.73=-4.9t^2+40t+100

We move all terms to the left:

4.73-(-4.9t^2+40t+100)=0

We get rid of parentheses

4.9t^2-40t-100+4.73=0

We add all the numbers together, and all the variables

4.9t^2-40t-95.27=0

a = 4.9; b = -40; c = -95.27;
Δ = b2-4ac
Δ = -402-4·4.9·(-95.27)
Δ = 3467.292
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{-(-40)-\sqrt{3467.292}}{2*4.9}=\frac{40-\sqrt{3467.292}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+\sqrt{3467.292}}{2*4.9}=\frac{40+\sqrt{3467.292}}{9.8}
$