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Precal Help???

0 votes
Express the sum without using sigma notation. Simplify your answer where possible.

3
Σ (n − 1)x^(n − 2)
n = 1
asked Jul 24, 2014 in PRECALCULUS by heather Apprentice

1 Answer

0 votes

Substitute 1, 2 and 3 in for n in the equation (n − 1)x n-2 and then add them together.

3
Σ (n − 1)x n-2 = (1-1)x 1-2 +(2-1) x 2-2 +(3-1)x 3-2
n = 1

                       =0+ 1x 0 + 2x

                        =1+2x

Therfore,

3
Σ (n − 1)x n-2 =1+2x
n = 1

 

answered Jul 24, 2014 by bradely Mentor

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