Question 246820
1) x^5-4x^3, x^3+4x^2+4x Instructions state to find LCM
To find any LCM find the prime factors of the numbers you are given:
x^5-4x^3 = x^3(x^2-4) = x^3(x-2)(x+2)
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x^3+4x^2+4x = x(x^2+4x+4) = x(x+2)^2
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Then the LCM is the product of each of the prime factors to their 
highest power.
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LCM = x^3*(x-2)(x+2)^2
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2)x^2/(x-7) + 49/(7-x)
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Rewrite as:
x^2/(x-7) - 49/(x-7)
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Since the denominators are the same, combine the numerators 
over the lcm.
(x^2-49)/(x-7)
Factor:
[(x+7)(x-7)]/(x-7)
Cancel to get the final answer:
x+7
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Cheers,
Stan H.