
Originally Posted by
RainieB
Could you please tell me why the + sign is changed to a - (minus) in this problem:
(-5) (x+4y+5)
= -5x + (-5) (4y) + (-5) (5)
= -5x - 20y - 25
they changed the + to - and 20y and 25 became positive instead of negative.
Does the first number outside of the parenthesis have something to do with this? It only happens when the first number is negative. Its a little confusing because thats not how we were taught to multiply signed numbers.
I really hope I get through this algebra stuff!!
Thanks again,
Rainie