-1 * (1 / 2) = - 1 + (1 / 2), - (1 / 2) + (1 / 3) = - (1 / 2) + (1 / 3), - (1 / 3) * (1 / 4) = - (1 / 3) + (1 / 4) (1) Rule: () is expressed by a formula containing N, where n is a positive integer (2) Use the above rule to calculate: (- 1 * (1 / 2)) + (- (1 / 2) * (1 / 3)) + (- (1 / 3) * (1 / 4)) +. + (- (1 / 2012) * (1 / 2013)) ask for the answer!

RELATED INFORMATIONS

• 1. (1 + 1) × 1 / 2 = 1, (1 + 1) × 2 / 2, (1 + 3) × 3 / 2, (1 + 4) × 4 / 2?
• 2. Summary rule: 1 / N (n + 1)=________ Using this law, we can calculate: half + one sixth + one twelfth + one twentieth + one thirtieth
• 3. From 11 × 2 = 12, 11-12 = 12; 12 × 3 = 16, 12-13 = 16; 13 × 4 = 112, 13-14 = 112 The conclusion is: 1n (n + 1)=______ Using this law, we can know that 11 × 2 + 12 × 3 + +1n(n+1)=______ ．
• 4. 1, - 2,3, - 4?
• 5. The following group of numbers are written according to a certain rule: - 1,2, - 3,4, - 5 ·······, then what is the nth number
• 6. Find the rule: 1-1 -, 2-2,3-4,4-8,5-16 find the nth number
• 7. The law of 1 * 2 * 3 * 4 * 5 * 6 * ····· n
• 8. -The law of 1 2 - 3 4 - 5 6 is expressed by n
• 9. Find the rule: 1 / 2, 1 and 2 / 3, 2 and 3 / 4, (), 4 and 5 / 6, ()
• 10. How much is it from 1 to 100?
• 11. What is the law of 1 + 2 = 3 and 4 + 3 + 2 + 1 + 1?
• 12. What's the rule of 2 / 3,1,3 / 2,9 / 4
• 13. 1/3+1/6+1/12+1/24+…… +1/3*2^n-1+…… = ditto
• 14. Fill in the number according to the law. (1 point) & nbsp; & nbsp; 1, 3, 2, 6, 4______ ，______ ，12，16，…
• 15. 1/2=1/1*2=1/1-1/2,1/6=1/2*3=1/2-1/3,1/12=1/3*4=1/3-1/4. Calculate 1 / (X-2) (x-3) - 2 / (x-1) (x-3) + 1 / (x-1) (X-2)
• 16. 1, 3, 2, 6, 4, (), (), 12 ()·····
• 17. What's the fastest formula from 1 10 2 10 3 to 100
• 18. How much is it from 1 to 100? What's the formula?
• 19. The formula from 1 to 100. Why (1 + 100) × (100 △ 2) be more detailed
• 20. 1 to 100 formula