Question

1/(x-4) + 1/(x+1) = (x^2-6)/(x^2-3x-4), solve for x.

Answer 1

notice that x^2-3x-4=(x-4)(x+1)
and x can not be 4 or -1 (why?)

Answer 2

Because it can't equal 0?

Answer 3

writte exactly the same on www.wolframalpha.com ....

Answer 4

remember u cannot divide by "0"

Answer 5

@alienshe
because the Denominator of a fraction can not be 0

Answer 6

now multiply both sides by (x-4)(x+1) and try to solve it
sure u can do it

Answer 7

I'm trying to do it right now and I'm not sure what to do next. 2x-x^2=-9

Answer 8

^ What I have now.

Answer 9

u did good
there is a little mistake
check it again u should get 2x-x^2=-3

Answer 10

I forgot to change the sign when I moved the -3. I do that too often...

Answer 11

What do I do now?...

Answer 12

ok now u have a quadratic equation x^2-2x-3=0
u can solve it by factoring or solving directly with quadratic equation formula

Answer 13

Why is it -2x and not +2x?

Answer 14

i moved 2x and -x^2 to the other side

Answer 15

am i right?

Answer 16

Oh. Yes. I moved -3 to the other side. Your way makes more sense, though.

Answer 17

ok

Answer 18

the standard form of a quadratic equation is
\[ax^2+bx+c=0\]
now u tell me what are a , b and c for our equation?

Answer 19

a=1, b=-2, c=-3.

Answer 20

I solved it by factoring and got x=3, -1.

Answer 21

I know the answer can't be -1. So x=3

Answer 22

very well

Answer 23

Thank you for your help! :) I really appreciate it.

Answer 24

u did it yourself.