about M.I

首先, 呢條唔係 M.I 問題,
只係證明 k/(2k+1)+1/((2k-1)(2 k+1)) = (k+1)/(2k+3) 既公式問題
第二,
當 k = 1,
左邊 = k/(2k+1)+1/((2k-1)(2 k+1)) = 1/(2+1)+1/((1)(3)) = 2/3
右邊 = (k+1)/(2k+3) = (1+1)/(2+3) = 2/5
兩邊都唔等...
你話點做??