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Jinglander
- Senior | Next Rank: 100 Posts
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- Joined: Thu Jul 22, 2010 5:40 pm
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2^x + 2^x would be 2 times 2^x or 2^ (x+1). Think of 2^x as "a". The original then is simply a+a = 2a.
If you had 3^x + 3^x you would only get 2(3^x).
You need to find a common factor. e.g.
2^(x+3) + 2(x+5) - the common factor is 2(x=3) therefore you get [2^(x+3) times 1] + [2^(x+3) times 2^2]
that gives you 2^(x+3) times (1+2^2) = 2^(x+3) time (1+4) = 5 times 2^(x+3)
Try picking numbers - as in the problem above - let x=2
2^(2+3) + 2^ (2+5) =2^5 + 2^7 = 32+128 = 160 = 5x 32 or 5 x 2^5 and you can see that with x = 2, 2^(x+3) = 2^5
