Quiz Math for Upgrade Your Skill hitunglah [tex] \dfrac{7}{6} + \dfrac{7}{12} + \dfrac{7}{20} + \cdots + \dfrac{1}{690} [/tex]

jawab

7 (1/6 + 1/12 + 1/20 + ...+ 1/4830)
7 [1/(2.3) + 1/(3.4) + 1/(4.5 ) +...+ 1/(69.70)]

7 [ 1/2 - 1/3  + 1/3 - 1/4 + ...+ 1/69 - 1/70]
7 [1/2 - 1/70]
7 [ 17/35]
= 17/5