SOLUTION: Find the LCD of 7 8 ----------- --, ------- a^2 + 2a - 63 a + 9

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Question 68800: Find the LCD of
7 8
--------------, -------
a^2 + 2a - 63 a + 9
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
LCD is the common denominator between each fraction that makes it possible to add and subtract. For instance to add 1/2 and 1/4, the LCD is 4 since 2/4 and 1/4 can be added. For this problem, you need to factor the left fraction first
%287%29%2F%28a%5E2+%2B+2a+-+63%29
%287%29%2F%28%28a%2B9%29%28a-7%29%29%29 If you FOIL (a+9)(a-7) you get a^2 + 2a - 63
You will then see that (a+9) is a common factor, so to complete the process, you need to multiply both sides by (a-7)/(a-7). Now you should see the LCD is (a+9)(a-7).