How do I find the least common denominatior of 3 fractions that have the term x? For example, when solving for 5/(x-1) - 7/x = 3/(2x-2), I see that the common denominator for these denominators is 2x(x-1). Why did not all the denominators get multiplied? How do I know what common denominator to use?

Question
Asked Sep 2, 2019

How do I find the least common denominatior of 3 fractions that have the term x? For example, when solving for 5/(x-1) - 7/x = 3/(2x-2), I see that the common denominator for these denominators is 2x(x-1). Why did not all the denominators get multiplied? How do I know what common denominator to use? 

 

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Expert Answer

Step 1

Given,

...
5
7
2х-2
x-1
5xx-7x(х-1)
3
(L.C.M of left-hand side is x(x -1)
x(х-1)
2 (х-1)
5х-7х+7
2
2(-2x 7) 3x
-4x 14 3x
— 4х — Зх
-14
-7x-14
x = 2
LO
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Image Transcriptionclose

5 7 2х-2 x-1 5xx-7x(х-1) 3 (L.C.M of left-hand side is x(x -1) x(х-1) 2 (х-1) 5х-7х+7 2 2(-2x 7) 3x -4x 14 3x — 4х — Зх -14 -7x-14 x = 2 LO

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Math

Algebra

Equations and In-equations