# Math Help - exponent problem

1. ## exponent problem

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2. Originally Posted by Revelsyn
I'm having some trouble with this one; I'm not sure how to multiply the neg n by the exponent "1 + n"

"evaluate."

2-n(2n - 21+n)

~everything in red is an exponent/the answer is suposed to be -1..
when multiplying numbers of the same base, we add the powers. that is,

$\displaystyle x^a \times x^b = x^{a + b}$

Note, $2^{-n} \left( 2^n - 2^{1 + n} \right) = 2^{-n} \cdot 2^n - 2^{-n} \cdot 2^{1 + n}$

Now continue using the rule above

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4. Didn't we see this before?

5. Originally Posted by Krizalid
Didn't we see this before?
It does look remarkably familiar doesn't it?