y^2-1=4y+3

Solution for y^2-1=4y+3 equation:

y^2-1=4y+3

We move all terms to the left:

y^2-1-(4y+3)=0

We get rid of parentheses

y^2-4y-3-1=0

We add all the numbers together, and all the variables

y^2-4y-4=0

a = 1; b = -4; c = -4;
Δ = b2-4ac
Δ = -42-4·1·(-4)
Δ = 32
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{32}=\sqrt{16*2}=\sqrt{16}*\sqrt{2}=4\sqrt{2}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-4\sqrt{2}}{2*1}=\frac{4-4\sqrt{2}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+4\sqrt{2}}{2*1}=\frac{4+4\sqrt{2}}{2}
$