Question 22728
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.