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As maths help wanted plllllleeeeeeeaaaaaassssseeeee!! !!!!!!

find the value of n for which Un=(-1) to the power of n multiplied by n/n+4=7/9
the answer is 14
Thank you
Simple cross multiplication will lead to, (-1)^n. [9n]=7n+28
Rearranging them would lead to, (-1)^n. [9n]-7n =28
I can't move further with the calculation because I'm not sure of the value of (-1)^n.
What could be the possibility of n? (1) n being even integers or (2) n being an odd integers.
So, (-1) raised to an even power will be equals to 1 as such 9n-7n=28 and n=14.

When n is odd, (-1)^n = -1 and -9n -7n=28, so n=-1.75!
But now, (-1) raised to a negative fractional power leads to an imaginary solution. So, n=-1.75 is rejected and n=14 is the answer. :smile:
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PhRose
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thank you sooooooooooooooooooooo much

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