7n^2-14n=245

Solution for 7n^2-14n=245 equation:

7n^2-14n=245

We move all terms to the left:

7n^2-14n-(245)=0

a = 7; b = -14; c = -245;
Δ = b2-4ac
Δ = -142-4·7·(-245)
Δ = 7056
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7056}=84$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-84}{2*7}=\frac{-70}{14}
=-5
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+84}{2*7}=\frac{98}{14}
=7
$