Question

if u answer all the questions I will make u as the brainliest ​

Answer 1

Answer:

11 is 3

12 is 1

13 is 2

14 is 1

15 is 4

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Answer 2

Answer:

11)c1+2c2/c1+3c3/c2+...+ncn/cn-1= n(n+1)/2

12)c0/1+c2/3+c4/5+c4/7+....=2^n/n+1

13)1²c1-2²c2+3²c3+....+(-1^n-1)n cn= 2^(n+1)/n-1

14)c0-c1/2+c2/3-c3/4=1/n+1

15)c0/2-c1/3+c2/4c3/5+....= 1/n+2

Step-by-step explanation: