If possible, factor 100 - 121y2.

(10 + 11y) (10 - 11y)

Step-by-step explanation:

100 - 121y²

This is a special factoring called difference of squares. Since both of the numbers in the subtraction expression are perfect squares, we can use this rule:

a² - b² = (√a² - √b²) (√a² + √b²)

Take the square root of each number. Add them in one bracket, subtract them in the other bracket.

(10 + 11y) (10 - 11y)

100 is a perfect square because its square root is a whole number.

√100 = 10

121y² is a perfect square because its square root is a whole number, and its variable is squared.

√121 = 11

√y² = y