a) 1 3/7 + 3/5 > 27/35
b) 1 > 1/2 + 1/4 + 1/8 + 1/16
`a)1 3/7+3/5=10/7+3/5=50/35+21/35=71/35>27/35`
`b)1/2+1/4+1/8+1/16=8/16+4/16+2/16+1/16=15/16<1`
a
\(1\dfrac{3}{7}+\dfrac{3}{5}=\dfrac{10}{7}+\dfrac{3}{5}=\dfrac{50}{35}+\dfrac{21}{35}=\dfrac{71}{35}\)
mà 71>27 nên 71/35>27/35
vậy \(1\dfrac{3}{7}>\dfrac{27}{35}\)
b
\(\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{1}{16}=\dfrac{8}{16}+\dfrac{4}{16}+\dfrac{2}{16}+\dfrac{1}{16}\)=\(\dfrac{8+4+2+1}{16}=\dfrac{15}{16}\)
1=\(\dfrac{1}{1}\)=\(\dfrac{16}{16}\)
mà 15<16 nên 15/16<16/16
vậy \(1>\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{1}{16}\)
`a)` vậy `=> : 71/35 > 27/35 (71 > 27)` hoặc `1 3/7 + 3/5 > 27/35`
`b)` vậy `1 < 5/4` hoặc` 1 < 1/2 + 1/4 + 1/8 + 1/16`
`a) 1 3/7 + 3/5` và `27/35`
ta có:
`1 3/7 + 3/5 = 10/7 + 3/5 = 71/35`
vậy `=> : 71/35 > 27/35 (71 > 27)` hoặc `1 3/7 + 3/5 > 27/35`
`b) 1` và `1/2 + 1/4 + 1/8 + 1/16`
Ta cs:
`1/2+1/4+1/8+1/16`
`=8/16+4/16+2/16+1/16`
`=(8+4+2+1)/16`
`=20/16=5/4`
Mà `5>4=>5/4>1`
Vậy `1<5/4` hoặc `1<1/2+1/4+1/8+1/16`
