Question

The product of (a − b)(a − b) is a2 − b2.

Sometimes

Always

Never

Answer 1

never. if you foil them out then you get a^2 -2ab +b^2. even if b is negative then it would be like two positive polymonials and you just get a^2 +2ab +b^2

Answer 2

Thank you!

Answer 3

you just have to account for all possibilities.
ie: both a and b are positive
a is positive, b is negative
a is negative, b is positive
both a and b are negative.

if you know how to foil just show what the answer to all 4 possibilities are and deduce from there if its never sometimes or always if you need to show your work