SOLUTION: The Problem is (15/x)+((9x-7)/(x+2))=9. I understand now how to do the simple equations but i just get confused when i see long denominators. I don't know how to find the LCM very

Algebra ->  Rational-functions -> SOLUTION: The Problem is (15/x)+((9x-7)/(x+2))=9. I understand now how to do the simple equations but i just get confused when i see long denominators. I don't know how to find the LCM very      Log On


   

Question 78447This question is from textbook Advanced Algebra
: The Problem is (15/x)+((9x-7)/(x+2))=9. I understand now how to do the simple equations but i just get confused when i see long denominators. I don't know how to find the LCM very well. This question is from textbook Advanced Algebra

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The Problem is (15/x)+((9x-7)/(x+2))=9. I understand now how to do the simple equations but i just get confused when i see long denominators. I don't know how to find the LCM very well.
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Your denominators are x, (x+2), and 1.
The lcm must contain each of the factors in their highest power.
For your problem that is x(x+2)
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So, multiply thru the equation by x(x+2) to get rid of the denominators:
15(x+2) + (9x-7)x =9x(x+2)
15x+30 + 9x^2-7x = 9x^2+18x
8x+30=18x
10x=30
x=3
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Checking you get: 15/3 + 20/5 = 9-----true
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Solution: x=3
Cheers,
Stan H.