3960=42y^2+y

Solution for 3960=42y^2+y equation:

3960=42y^2+y

We move all terms to the left:

3960-(42y^2+y)=0

We get rid of parentheses

-42y^2-y+3960=0

We add all the numbers together, and all the variables

-42y^2-1y+3960=0

a = -42; b = -1; c = +3960;
Δ = b2-4ac
Δ = -12-4·(-42)·3960
Δ = 665281
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{665281}}{2*-42}=\frac{1-\sqrt{665281}}{-84}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{665281}}{2*-42}=\frac{1+\sqrt{665281}}{-84}
$