-9+t2=56

Solution for -9+t2=56 equation:

-9+t2=56

We move all terms to the left:

-9+t2-(56)=0

We add all the numbers together, and all the variables

t^2-65=0

a = 1; b = 0; c = -65;
Δ = b2-4ac
Δ = 02-4·1·(-65)
Δ = 260
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:

$\sqrt{\Delta}=\sqrt{260}=\sqrt{4*65}=\sqrt{4}*\sqrt{65}=2\sqrt{65}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{65}}{2*1}=\frac{0-2\sqrt{65}}{2}
=-\frac{2\sqrt{65}}{2}
=-\sqrt{65}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{65}}{2*1}=\frac{0+2\sqrt{65}}{2}
=\frac{2\sqrt{65}}{2}
=\sqrt{65}
$