3=3+60t-16t^2

Solution for 3=3+60t-16t^2 equation:

3=3+60t-16t^2

We move all terms to the left:

3-(3+60t-16t^2)=0

We get rid of parentheses

16t^2-60t-3+3=0

We add all the numbers together, and all the variables

16t^2-60t=0

a = 16; b = -60; c = 0;
Δ = b2-4ac
Δ = -602-4·16·0
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-60}{2*16}=\frac{0}{32}
=0
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+60}{2*16}=\frac{120}{32}
=3+3/4
$