2a^2-28a=960

Solution for 2a^2-28a=960 equation:

2a^2-28a=960

We move all terms to the left:

2a^2-28a-(960)=0

a = 2; b = -28; c = -960;
Δ = b2-4ac
Δ = -282-4·2·(-960)
Δ = 8464
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8464}=92$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-28)-92}{2*2}=\frac{-64}{4}
=-16
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+92}{2*2}=\frac{120}{4}
=30
$