3.75=-16t^2+60t+25

Solution for 3.75=-16t^2+60t+25 equation:

3.75=-16t^2+60t+25

We move all terms to the left:

3.75-(-16t^2+60t+25)=0

We get rid of parentheses

16t^2-60t-25+3.75=0

We add all the numbers together, and all the variables

16t^2-60t-21.25=0

a = 16; b = -60; c = -21.25;
Δ = b2-4ac
Δ = -602-4·16·(-21.25)
Δ = 4960
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:

$\sqrt{\Delta}=\sqrt{4960}=\sqrt{16*310}=\sqrt{16}*\sqrt{310}=4\sqrt{310}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-4\sqrt{310}}{2*16}=\frac{60-4\sqrt{310}}{32}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+4\sqrt{310}}{2*16}=\frac{60+4\sqrt{310}}{32}
$