Can anyone tell me how you get from step A to B?
A) (5/3)^k + (5/3)^k-1
B) ((5/3)^k-1) x ((5/3)+1)
I just don't understand what steps to take to get from A to B. It goes from addition to multiplication, the exponents change, and then a 1 shows up. Any help? Its probably harder to picture when its typed out like that instead of on paper.
A) (5/3)^k + (5/3)^k-1
B) ((5/3)^k-1) x ((5/3)+1)
I just don't understand what steps to take to get from A to B. It goes from addition to multiplication, the exponents change, and then a 1 shows up. Any help? Its probably harder to picture when its typed out like that instead of on paper.
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First notice that (5/3)*(5/3)^(k-1) = (5/3)^(k-1+1) = (5/3)^ k
it means that you can replace (5/3)^k by (5/3)*(5/3)^(k-1)
So you can write A as
(5/3)^(k-1)*(5/3) + (5/3)^(k-1)
Now factor out (5/3)^(k-1) to get B
(5/3)* (5/3)^(k-1) + (5/3)^(k-1) = (5/3)^k-1 (5/3 +1)
it means that you can replace (5/3)^k by (5/3)*(5/3)^(k-1)
So you can write A as
(5/3)^(k-1)*(5/3) + (5/3)^(k-1)
Now factor out (5/3)^(k-1) to get B
(5/3)* (5/3)^(k-1) + (5/3)^(k-1) = (5/3)^k-1 (5/3 +1)