Question

Express 9 - y2 as the product of two binomial factors

Answer 1

Binomial factors are where two factors are being added. For a²-b², it can be written as (a-b)*(a+b). Writing it out, we know that 9=3², so we can make it
 (3-y)(3+y)

Answer 2

$9 - y^2$ 

$3^2-y^2$ 

$(3+y)(3-y)$