-3t^2+66t-63=0

Solution for -3t^2+66t-63=0 equation:

-3t^2+66t-63=0

a = -3; b = 66; c = -63;
Δ = b2-4ac
Δ = 662-4·(-3)·(-63)
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{-(66)-60}{2*-3}=\frac{-126}{-6}
=+21
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(66)+60}{2*-3}=\frac{-6}{-6}
=1
$