Question

Find the LCD of: x, X-2, and x^2-2x

Answer 1

@Directrix

Answer 2

What is in the denominator

Answer 3

Sorry. It came out crappy. Bad. Heres how its suppose to actually be:

Answer 4

\[\frac{ 3 }{ x }+\frac{ 6 }{ x-2 }=\frac{ 12 }{ x ^{2}-2x }\]

Answer 5

BUT .. all i need to do is find the LCD which the LCD is x(x-2)

BUT ... he said I must use the LCD chart.

Answer 6

Which is like this : http://www.youtube.com/watch?v=P-GHtf9MOCk

BUT ... Im not ending up with the right answer.

Answer 7

The LCD is \[x ^{2} - 2x\]I don't know the LCD chart

Answer 8

The LCD Chart is in the video.

Its like ..... Find the LCD the way of finding the LCM .

Answer 9

@Directrix

Answer 10

I don't know the term "LCD Chart" so I'm over on YouTube watching this 11-minute video to see if I recognize it.

Answer 11

@DocLav I did that. I multiplied x (times) x-2 ..... resulted to: x(x-2)

BUT ..... using the chart .... you bring down it all because they appear once:

\[x \times x-2 \times x(x-2) you will get: x ^{2} - 2x(x-2)\]

Answer 12

I don't know then. Tell your teacher his LCD chart is stupid and a doctor said that. Ha

Answer 13

Hahaa, yeah, it doesn't make much sense. I think the LCD Chart works best for numbers you don't have to factor.

Answer 14

It is making sense. I'm on the LCM portion of the video.

Answer 15

Yeah. If there are no variables than it may work better.

Answer 16

No you don't multiply them all together. That is not how you find LCM.
From first row you bring x down first. From second row you bring down (x-2). The third row has x and (x-2). But we already brought down x and (x-2). So we don't have to bring anything down from the third row.

Answer 17

@rbeckford134 Post the chart you made, please.

Answer 18

@Ranga ... that made a lot of sense!

I think I did the chart correctly that i posted just now?

Answer 19

That is how the chart I made from the video looks.

LCD = x*(x-2)

Answer 20

Your chart is correct for the three rows. But from each row we have to see which factors to bring down to find LCD. From the first row you bring x down. From the second row you bring (x-2) down. When we look at the third row it has an x and a (x-2). Those two are already covered before. So nothing more to bring down. So for LCD you are left with x * (x-2)

Answer 21

Let us try an example with numbers. Find the LCD of
1/3, 1/4 and 1/12
1sr row : 3: 3
2nd row: 4: 4
3rd row: 12: 3 x 4

From the first row drop down 3. From second row drop down 4. The third row has 3 and 4. But we have already covered 3 and 4 before and so we don't have to do it again.
So the LCD will be 3 x 4 = 12

Answer 22

Ohhh ! I seee ! So once you bring the down number once before ... you don't need to bring it down again!

Answer 23

Exactly. The whole idea in finding LCD or LCM is to come up with the minimum number of factors that covers ALL rows.

Answer 24

In the number example above, the LCD is 3 x 4. The first row has a 3 and we have that covered in our LCD. The second row has a 4 and we have that covered in the LCD. The third row has 3 x 4. We have both those factors covered in our LCD. So 3 x 4 is our LCD. The least number of factors that includes all factors in each row.

Answer 25

How would you solve:


\[\left| 6x ^{2} \right| 2 \times 3 \times x^{2}\]
\[\left| 2x \right| 2 \times 2 \times x\]
\[\left| 3x \right| 3 \times x \]

Answer 26

What do you mean solve. It is not an equation.

Answer 27

Sorry.

2 (3) = 6x^2

Answer 28

You can multiply 2 and 3 on the left. Then divide both sides by 6. What do you get?

Answer 29

you get 1

Answer 30

1 on the left but you have to divide on the right too.

Answer 31

x^2

Answer 32

1 = x^2 or
x^2 = 1
Take square root on both sides
and you get x = sqrt(1) = +1 or -1

So x = plus or minus 1 is the solution.

Answer 33

ooooh okay ! Cool Cool ! Thanks!!!

Answer 34

You are welcome.