Write the polynomial as a product of a difference and a sum

Question

y^2–0.09

y²–0.09

Answer 1

Recognize that

 

y² - 0.09

 

is a difference of squares.  It has the form

 

a² - b² = (a - b)(a + b)

 

where a = y and b = 0.3

 

Then

 

y² - 0.09 = y² - 0.3² = (y - 0.3)(y + 0.3)