60=256-64t^2

Solution for 60=256-64t^2 equation:

60=256-64t^2

We move all terms to the left:

60-(256-64t^2)=0

We get rid of parentheses

64t^2-256+60=0

We add all the numbers together, and all the variables

64t^2-196=0

a = 64; b = 0; c = -196;
Δ = b2-4ac
Δ = 02-4·64·(-196)
Δ = 50176
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{50176}=224$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-224}{2*64}=\frac{-224}{128}
=-1+3/4
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+224}{2*64}=\frac{224}{128}
=1+3/4
$