4t^2-28t-6t^2-12t=26

Solution for 4t^2-28t-6t^2-12t=26 equation:

4t^2-28t-6t^2-12t=26

We move all terms to the left:

4t^2-28t-6t^2-12t-(26)=0

We add all the numbers together, and all the variables

-2t^2-40t-26=0

a = -2; b = -40; c = -26;
Δ = b2-4ac
Δ = -402-4·(-2)·(-26)
Δ = 1392
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:

$\sqrt{\Delta}=\sqrt{1392}=\sqrt{16*87}=\sqrt{16}*\sqrt{87}=4\sqrt{87}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-4\sqrt{87}}{2*-2}=\frac{40-4\sqrt{87}}{-4}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+4\sqrt{87}}{2*-2}=\frac{40+4\sqrt{87}}{-4}
$