1.25=-16t^2+32t+20

Solution for 1.25=-16t^2+32t+20 equation:

1.25=-16t^2+32t+20

We move all terms to the left:

1.25-(-16t^2+32t+20)=0

We get rid of parentheses

16t^2-32t-20+1.25=0

We add all the numbers together, and all the variables

16t^2-32t-18.75=0

a = 16; b = -32; c = -18.75;
Δ = b2-4ac
Δ = -322-4·16·(-18.75)
Δ = 2224
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:

$\sqrt{\Delta}=\sqrt{2224}=\sqrt{16*139}=\sqrt{16}*\sqrt{139}=4\sqrt{139}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-32)-4\sqrt{139}}{2*16}=\frac{32-4\sqrt{139}}{32}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-32)+4\sqrt{139}}{2*16}=\frac{32+4\sqrt{139}}{32}
$