\(\Rightarrow\)2/1*3+2/3*5+...+2/x(x+2)=\(\frac{16}{17}\)

\(\Rightarrow\)1-1/3+1/3-1/5+...+1/x-1/x+2=16/17

\(\Rightarrow\)1-1/x+2=16/17\(\Rightarrow\)1/x+2=1/17

\(\Rightarrow\)x+2=17\(\Rightarrow\)x=15

Vậy.....

\(\Rightarrow\)

D nha bạn

f1(x);f5(x)