先观察：1-12=11×212-13=12×313-14=13×414-15=14×5再用简便方法计算：12+16+112+120+130．

Question

先观察：
1-(1)/(2)=(1)/(1×2)
(1)/(2)-(1)/(3)=(1)/(2×3)
(1)/(3)-(1)/(4)=(1)/(3×4)
(1)/(4)-(1)/(5)=(1)/(4×5)
再用简便方法计算：
(1)/(2)+(1)/(6)+(1)/(12)+(1)/(20)+(1)/(30)．

Answer 1

(1)/(2)+(1)/(6)+(1)/(12)+(1)/(20)+(1)/(30)
=1-(1)/(2)+(1)/(2)-(1)/(3)+(1)/(3)-(1)/(4)+(1)/(4)-(1)/(5)+(1)/(5)-(1)/(6)
=1-(1)/(6)
=(5)/(6)．