35=s^2-2s

Solution for 35=s^2-2s equation:

35=s^2-2s

We move all terms to the left:

35-(s^2-2s)=0

We get rid of parentheses

-s^2+2s+35=0

We add all the numbers together, and all the variables

-1s^2+2s+35=0

a = -1; b = 2; c = +35;
Δ = b2-4ac
Δ = 22-4·(-1)·35
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-12}{2*-1}=\frac{-14}{-2}
=+7
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+12}{2*-1}=\frac{10}{-2}
=-5
$