SOLUTION: please factor the following using the foil method so i am able to do the rest of the problems on my own thanks so much for your help. b^2 + 7b - 8 =

Algebra ->  Equations -> SOLUTION: please factor the following using the foil method so i am able to do the rest of the problems on my own thanks so much for your help. b^2 + 7b - 8 =       Log On


   

Question 22728: please factor the following
using the foil method so i am able to do the rest of the problems on my own
thanks so much for your help.
b^2 + 7b - 8 =
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
you need 2 numbers that multiply to give 8 and then add/subtract to give 7

Possible pairings are: 8x1 and 4x2

which pair can add/subtract to give 7? answer is 8 and 1...so, we have (b 8)(b 1)

Now, we need to figure out the signs:

They multiply to give -8, so 2 possibilities are either (+8 and -1) OR (-8 and +1)

These have to combine to give +7: only one that does that is +8 and -1... so the answer is (b+8)(b-1)

jon.