Factor 1-4y^2

$1 - 4 y^{2}$

Step 1

Rewrite $1$ as $1^{2}$ .

$1^{2} - 4 y^{2}$

Step 2

Rewrite $4 y^{2}$ as ${(2 y)}^{2}$ .

$1^{2} - {(2 y)}^{2}$

Step 3

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 1$ and $b = 2 y$ .

$(1 + 2 y) (1 - (2 y))$

Step 4

Multiply $2$ by $- 1$ .

$(1 + 2 y) (1 - 2 y)$