I have a test over factoring polynomials tomorrow. Most of it i have fairly well understood, but there's an extra credit section with problems we haven't discussed yet. I am not doing fantastic in math right now, so i could really use the bonus points. Can someone help explain them?

Factor Completely. (Bi) (Bi)

Also, how can you determine in an answer in the format of (x + 1)(x - 2) whether it will be a +-, -+, ++, or -- answer?