x2 + 6x – 7
x2 – 1
How do you solve this problem. Thanks
2006-10-31 13:07:31 · 10 answers · asked by neish 1 in Science & Mathematics ➔ Mathematics
You almost got it, keep going.
2006-10-31 13:09:02 · answer #1 · answered by D.J 5 · 1⤊ 1⤋
This is not a rational expression. A rational expression would have to be a fraction in the form A/B or A divided by B where B connot equal to zero.
What you have here is a trinomial---a polynomial of three terms.
Also, you need to use proper keyboard system or else your question does not make sense for math tutors to follow.
Your trinomial should be typed this way:
x^2 + 6x - 7
You need to factor the trinomial.
You have three terms:
term 1 is x^2
term 2 is 6x
term 3 is -7
See it?
Ask yourself:
What TWO NUMBERS when multiplied will produce -7 (your third term) but when adding the same TWO NUMBERS will give you the MIDDLE TERM, which in this case is 6x?
Hey, how about 7 times -1?
Well, 7 times -1 = -7, right?...This is our third term.
When adding 7 and -1, I get 6, which is the coefficient of the middle term. See it?
We now need to create two parentheses where to place our factors.
x^2 + 6x - 7 becomes: (x + 7) (x-1)
One last thing:
(x+7) and (x-1) are the TWO FACTORS of your original trinomial.
Final answer: (x+7) (x-1)
Guido
2006-10-31 21:19:47 · answer #2 · answered by Anonymous · 0⤊ 0⤋
x2 + 6x = 7
divide all of left side by x
x + 6 = 7
subtract 6 on both sides
x = 1
2006-10-31 21:10:24 · answer #3 · answered by Sylvie M 3 · 0⤊ 0⤋
By factoring it, you get (x+7)(x-1) which equals x2 + 6x - 7
2006-10-31 21:09:27 · answer #4 · answered by beachbuhm11 1 · 0⤊ 1⤋
non has solved both problems
1) if rational soluttion exists find rational factors of -7 so that sum is 6
-7 = 7*(-1) or -7 *1
sum of 7 and -1 = 6
so x^2+7x-x-7
= x(x+7)-1(x+7)
= (x-1)(x+7)
2) it is even simpler
a^2-b^2 = (a-b)(a+b)
put a= x and b = 1
(x^2-1) = (x-1)(+1)
2006-10-31 21:24:49 · answer #5 · answered by Mein Hoon Na 7 · 0⤊ 0⤋
You have to factor it. That is, set it equal to zero.
Ask yourself,
"What times what equals -7, but at the same time, what plus what equals 6????"
After some time, you'll see that 7 and -1 fit pretty well
(x+7)(x-1)
2006-10-31 21:10:22 · answer #6 · answered by Anonymous · 1⤊ 0⤋
x2=6x-7
+7= +7
9x=6x
6 6
1.5x
2006-10-31 21:10:14 · answer #7 · answered by milesheywood19 1 · 0⤊ 1⤋
(x^2+6x-7)/(x^2-1)
(x+7)(x-1)/((x+1)(x-1) the (x-1)'s cancel
(x+7)/(x+1)
2006-10-31 21:11:19 · answer #8 · answered by Greg G 5 · 0⤊ 0⤋
well add like terms so 2x and 6x is 8x and leave the seven as is.. so it will be 8x-7. And the second one is just 2x-1.
2006-10-31 21:09:06 · answer #9 · answered by coolchess123 3 · 0⤊ 1⤋
Simply, its a couple of x's along with a few numbers, and several plusses and minuses thrown in along the way
2006-10-31 21:10:09 · answer #10 · answered by Anonymous · 0⤊ 1⤋