(y+1)(y-1)=3

Solution for (y+1)(y-1)=3 equation:

Simplifying
(y + 1)(y + -1) = 3

Reorder the terms:
(1 + y)(y + -1) = 3

Reorder the terms:
(1 + y)(-1 + y) = 3

Multiply (1 + y) * (-1 + y)
(1(-1 + y) + y(-1 + y)) = 3
((-1 * 1 + y * 1) + y(-1 + y)) = 3
((-1 + 1y) + y(-1 + y)) = 3
(-1 + 1y + (-1 * y + y * y)) = 3
(-1 + 1y + (-1y + y2)) = 3

Combine like terms: 1y + -1y = 0
(-1 + 0 + y2) = 3
(-1 + y2) = 3

Solving
-1 + y2 = 3

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '1' to each side of the equation.
-1 + 1 + y2 = 3 + 1

Combine like terms: -1 + 1 = 0
0 + y2 = 3 + 1
y2 = 3 + 1

Combine like terms: 3 + 1 = 4
y2 = 4

Simplifying
y2 = 4

Take the square root of each side:
y = {-2, 2}