Quick Homework Help

# Can someone please explain to me how A*-B and B*A become additive inverses? ⚑ Flag

by Sunshine at December 11, 2009

When you multiply them out, you get -ab and +ab. If you add those, you get 0. That's the definition of additive inverses... the +and- of the same number added together to get 0. Just like 6 and -6 or 35 and -35 are additive inverses. Basically, when you FOIL this out you get: a^2 + ab - ab - b^2 Combine like terms in the middle to get: a^2 + 0 - b^2, or just... a^2 - b^2. That's where the special case she gave is derived from.

bpeters December 16, 2009

your avatar is really "nice"

moechris001 January 06, 2010

bpeters is right!! thats how you would do it and figure it out!! and the F.O.I.L. means: F = first O = outer  I  = inner  L = last * just a reminder!! * GOOD LUCK!!

a_s_h_l_e_e February 25, 2010

mines cooler :P

DanielJung July 29, 2010

oh to answer your question, Additive Inverses just mean numbers that are opposite from each other, such as +6 and -6. If you add A*-b and B*A, you get 0 :).

DanielJung July 29, 2010