7/8=1/8+1/4+1/2=2/4+2/8+2/16=...

đưa nội quy làm gì

7/8 nha bn

học tốt

7/8=?????????????????????????????????????????????????????????????????

7/8=7/24+7/24+7/24

đúng k bạn?? 

\(\frac{7}{8}\)= \(\frac{1}{8}\)+ \(\frac{1}{4}\)+ \(\frac{1}{2}\)

8/10=1/2+1/5+1/10

9/15=1/3+1/5+1/15

7/8=1/2+1/4+1/8

8/10=1/2+1/5+1/10

9/15=1/3+1/5+1/15

7/8=1/2+1/4+1/8

7 / 8 = 1 / y + 1 / x + 1 / a 

7 / 8 = 21 / 24

1 / 2 = 12 / 24

1 / 3 = 8 / 24

1 / 4 = 6 / 24 

............

 tiếp tục suy luận sẽ ra

\(a,\)                \(\frac{7}{8}=\frac{1+2+4}{8}=\frac{1}{8}+\frac{2}{8}+\frac{4}{8}=\frac{4}{32}+\frac{4}{16}+\frac{4}{8}\)

\(\text{b,}\)                  \(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right).\left(1-\frac{1}{5}\right)\)

                    \(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.\frac{4}{5}\)

                    \(=\frac{1}{5}\)

B)(1-1/2).(1-1/3).(1-1/4).(1-1/5)

= (2/2-1/2).(3/3-1/3).(4/4-1/4).(5/5-1/4)

=1/2.2/3.3/4.4/5

=1.2.3.4/2.3.4.5=1.2.3.4/2.3.4.5=1/5

\(\frac{7}{8}=\frac{1}{2}+\frac{1}{3}+\frac{1}{24}\)

\(\frac{7}{8}\)= \(\frac{1}{8}\)+ \(\frac{2}{8}\)+ \(\frac{4}{8}\)

\(\frac{7}{8}\)= \(\frac{2}{8}\)+ \(\frac{2}{8}\)+ \(\frac{3}{8}\)

\(\frac{7}{8}=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}\)