2007-05-27 14:58:21 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
(x + 8) (x - 7)
because -7 + 8 = 1 amd -7 * 8 = -56
2007-05-27 15:02:15 · answer #1 · answered by polkadots 2 · 0⤊ 0⤋
The answer to a problem like this is always going to be in this form:
(x + a)*(x + b)
which is x^2 + ax + bx + ab
So to figure out what a and b are, you need values of a and b whose product is -56 and whose sum is +1 (the coefficient of the middle term x).
I don't know of any easy to do this except by trial and error.
Fortunately, there aren't too many factors of 56, and the obvious ones are 8 and 7. Since the sum needs to be +1, use +8 and -7.
2007-05-27 15:22:52 · answer #2 · answered by Tom K 2 · 0⤊ 0⤋
x^2+x-56
(x+8)(x-7)
2007-05-27 15:36:08 · answer #3 · answered by yupchagee 7 · 0⤊ 0⤋
(x + 8).(x - 7)
Check
x.(x + 7) + 8.(x - 7)
= x² + 7x + 8x - 56
= x² + 15x - 56 (as required)
2007-05-27 21:14:05 · answer #4 · answered by Como 7 · 0⤊ 0⤋
(x-7) (x+8)
2007-05-27 15:10:26 · answer #5 · answered by Anthony 1 · 0⤊ 0⤋
(x+8)(x-7)
2007-05-27 15:00:15 · answer #6 · answered by jsoos 3 · 1⤊ 0⤋