Question

[Trần Duy Quân]

1/2 + 1/6 + 1/12 + 1/20 + 1/30 =

Ai làm đúng mình sẽ tick cho.

Answer 1

[Alice]

1/2 + 1/6 + 1/12 + 1/20 +1/30 

= 30/60 + 10/60 + 5/60 + 3/60 + 2/60

= (30+10+5+3+2)/60

= 50/60 = 5/6

Answer 2

[Mai Anh Pen tapper]

\(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}\)

\(=1-\frac{1}{2}+\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{6}\)

\(=1-\frac{1}{6}\)

\(=\frac{5}{6}\)