solve each equation. Check your answers and identify any extraneous roots. x - 2/x^2 - x - 6 = 1/x^2-4 + 3/2x + 4=
@ganeshie8 think u can help?
is the question pasted correctly
= in the end is throwing me off
ignore that equal sign.
i had to write it out cause its on paper. -.-
\(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4}\)
in your paper, is the question looking as above ?
yess
this requires lot of paper !
ya it looks like it..lol
ok lets do it
do you knw factoring ?
not really i never took algebra 2 in a classroom so i dont know anything :/
its okay factoring is easy
lets start wid factoring bottom :- x^2-x-6
we need to write that as product of two things. thats called factoring
oh ok
this is how we going to factor it : x^2 - x - 6 x^2 -3x + 2x -6 x(x-3) + 2(x-3) (x-3)(x+2)
make sure you understand how we factored, we going to do the same for many future problems. so you need to understand them if u want to feel comfortable when solving other problems later. ok. so just make sure u understand how to factor. if u dont, just ask ok
take ur time
ok how did you get 3x & the extra 2x?
good q, didnt u notice x is missing
x^2 - x - 6 x^2 -3x + 2x -6
yes & also the addition symbol
we need to rewrite the middle "-x"
i wrote, "-3x + 2x" in place of "-x"
il tell why we picked those soon, but do u agree that there is nothing wrong in what we did ?
cuz, -3x + 2x = -x
yes i seee
ok, lets move on. (il tell you how to pick the numbers later)
x^2 - x - 6 x^2 -3x + 2x -6
ok sounds good!
from the first two terms, take x common
x^2 - x - 6 x^2 -3x + 2x -6 x(x-3) + 2x - 6
still wid me ?
from the last two terms take 2 common
x^2 - x - 6 x^2 -3x + 2x -6 x(x-3) + 2x - 6 x(x-3) + 2(x-3)
now we see (x-3) is common in both terms, so take it common !
x^2 - x - 6 x^2 -3x + 2x -6 x(x-3) + 2x - 6 x(x-3) + 2(x-3) (x-3)(x+2)
ok im kinda with you :p
we are done factoring ! just go thru and make yourself convinced u understand
so bottom x^2-x-6 can be written in factored form as (x-3)(x+2). lets go to our main equation
okaay
\(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \)
\(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \)
next look at right side of equation. lets keep focusing on bottom
we have x^2-4
i want to factor it.
can u help me if u have any ideas how to factor it ?
lemme try
heres the clue :- write 4 as 2^2 and use the formula, a^2-b^2 = (a+b)(a-b)
ok il help you wid this
x^2 - 4 x^2 - 2^2 (x+2)(x-2)
we used a^2-b^2 formula, when moving from 2nd step to 3rd step
we have our main working as :- \(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2x + 4} \)
look at the bottom of last term. 2x+4 2(x+2)
\(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2(x + 2)} \)
if you see (x+2) is there in the bottom for each term. so it can be cancelled
\(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2(x + 2)} \) \(\large \frac{ x - 2}{(x-3)\cancel{(x+2)}} = \frac{1}{\cancel{(x+2)}(x-2)} + \frac{3}{2\cancel{(x + 2)}} \) \(\large \frac{ x - 2}{(x-3)} = \frac{1}{(x-2)} + \frac{3}{2} \)
you still wid me or i lost u lol, this is a very lengthy prob. but simple one.
ya im with you im just trying to write it out too to understand it >.<
good :) thats the only simplification possible by factoring. now we need to do the donkey work. get ready
lol ok lets do this.
\(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2(x + 2)} \) \(\large \frac{ x - 2}{(x-3)\cancel{(x+2)}} = \frac{1}{\cancel{(x+2)}(x-2)} + \frac{3}{2\cancel{(x + 2)}} \) \(\large \frac{ x - 2}{(x-3)} = \frac{1}{(x-2)} + \frac{3}{2} \) \(\large \frac{ x - 2}{(x-3)} = \frac{2+3(x-2)}{2(x-2)}\) \(\large \frac{ x - 2}{(x-3)} = \frac{2+3x-6)}{2(x-2)}\) \(\large \frac{ x - 2}{(x-3)} = \frac{3x-4)}{2(x-2)}\)
i just took the LCD of right side, so we can write it as single term. instead of 2 terms. u knw LCD ?
least common denominator?
exactly ! LCD of 2, (x-2) is simply 2(x-2)
let me knw once u follow upto above steps. we can go ahead with rest of the problem, then
i follow
great :)
\(\large \frac{ x - 2}{x^2 - x - 6} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{x^2-4} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2x + 4} \) \(\large \frac{ x - 2}{(x-3)(x+2)} = \frac{1}{(x+2)(x-2)} + \frac{3}{2(x + 2)} \) \(\large \frac{ x - 2}{(x-3)\cancel{(x+2)}} = \frac{1}{\cancel{(x+2)}(x-2)} + \frac{3}{2\cancel{(x + 2)}} \) \(\large \frac{ x - 2}{(x-3)} = \frac{1}{(x-2)} + \frac{3}{2} \) \(\large \frac{ x - 2}{(x-3)} = \frac{2+3(x-2)}{2(x-2)}\) \(\large \frac{ x - 2}{(x-3)} = \frac{2+3x-6)}{2(x-2)}\) \(\large \frac{ x - 2}{(x-3)} = \frac{3x-4)}{2(x-2)}\) Cross multuply \(\large 2(x-2)^2 = (3x-4)(x-3)\)
how do i set that up to cross multiply?
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