Find a positive value of the given variable so that the trinomial is factorable.
x2 + bx - 5; b = ?
6
4
5
7
2007-07-20 08:14:16 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
You mean x^2, not x2, right?
If it's to be factorable, then b must be the sum of 2 intergers, one negative and one positive, whose product is -5. There are only 2 pairs of integer factors of -5, (-1,5) and (1,-5). The only one whose sum is in your list is (-1,5), which is 4, so b=4.
If b=4, then the trinomial can be factored into
(x+5)(x-1)
2007-07-20 08:24:57 · answer #1 · answered by Gary H 6 · 0⤊ 1⤋
4
2007-07-20 15:22:36 · answer #2 · answered by Anonymous · 0⤊ 0⤋
b=4
2007-07-20 15:19:34 · answer #3 · answered by harry m 6 · 0⤊ 0⤋
you could use anyone of these #s as B and the trinomial would be factorable, but 3 of the four would have messy decimal places. The only option with a clean answer is to use 4 as B. It would factor out to (x-1)(x+5)
2007-07-20 15:22:56 · answer #4 · answered by Dan S 2 · 0⤊ 0⤋
x^2 + bx - 5
=(x-1)(x+5)
b=4
2007-07-20 15:23:12 · answer #5 · answered by iyiogrenci 6 · 0⤊ 0⤋
This is not a complet equation.....
it could be...x^2 +bx-5=0
or >>>>>>>>=1 or 2 or any number
next time write the correct eq'n...
or may be the problem is with me I havent seen an equation like this before...
2007-07-20 15:26:34 · answer #6 · answered by CuriousG 3 · 0⤊ 0⤋
The obvious factoring is:
(x + 5)(x - 1)
... which results in b=4.
2007-07-20 15:20:09 · answer #7 · answered by McFate 7 · 0⤊ 0⤋
4
what two numbers multiply to give five
they are 1 and 5
the numbers have different signs due to the minus in front of the five.
thus,
5 minus 1 is 4
the factors are (x-1)(x+5)
2007-07-20 15:18:23 · answer #8 · answered by Kris Z 4 · 0⤊ 0⤋
4.
x^2 + 5x - x - 5 = (x+5) (x-1)
2007-07-20 15:20:04 · answer #9 · answered by Saif 2 · 0⤊ 0⤋