4(4t^2-225)=0

Solution for 4(4t^2-225)=0 equation:

4(4t^2-225)=0

We multiply parentheses

16t^2-900=0

a = 16; b = 0; c = -900;
Δ = b2-4ac
Δ = 02-4·16·(-900)
Δ = 57600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{57600}=240$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-240}{2*16}=\frac{-240}{32}
=-7+1/2
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+240}{2*16}=\frac{240}{32}
=7+1/2
$