1 / 2 = 1-1 / 2, 1 / 6 = 1 / 2-1 / 3, 1 / 12 = 1 / 3-1 / 4. According to the above rule, calculate the following questions: 1 / 2 + 1 / 6 + 1 / 12 + 1 / 20 + 1 / 30

1 / 2 = 1-1 / 2, 1 / 6 = 1 / 2-1 / 3, 1 / 12 = 1 / 3-1 / 4. According to the above rule, calculate the following questions: 1 / 2 + 1 / 6 + 1 / 12 + 1 / 20 + 1 / 30

Are you wrong? It should be 1 / X (x + 1)
Then 1 / X (x + 1) = 1 / X-1 / (x + 1) according to the above formula
So the original formula = 1 / X-1 / (x + 1) + 1 / (x + 1) - 1 / (x + 2) +... + 1 / (x + 4) - 1 / (x + 5) = 1 / X-1 / (x + 5) = 5 / X (x + 5)