Toán A=2015/2016+2016/2017+2017/2018+2018/2015 chứng minh A lớn hơn 4 08/09/2021 By Brielle A=2015/2016+2016/2017+2017/2018+2018/2015 chứng minh A lớn hơn 4
Đáp án: Giải thích các bước giải: `A=\frac{2015}{2016}+\frac{2016}{2017}+\frac{2017}{2018}+\frac{2018}{2015}` `=\frac{2016-1}{2016}+\frac{2017-1}{2017}+\frac{2018-1}{2018}+\frac{2015+3}{2015}` `=1-\frac{1}{2016}+1-\frac{1}{2017}+1-\frac{1}{2018}+1+\frac{3}{2015}` `=4+(\frac{1}{2015}-\frac{1}{2016})+(\frac{1}{2015}-\frac{1}{2017})+(\frac{1}{2015}-\frac{1}{2018})` `=4+\frac{2016-2015}{2015.2016}+\frac{2017-2015}{2015.2017}+\frac{2018-2015}{2015.2018}` `=4+\frac{1}{2015.2016}+\frac{2}{2015.2017}+\frac{3}{2015.2018}` `>4+0+0+0=4(đpcm)` Trả lời
Đáp án: A>4 Giải thích các bước giải: A=2015/2016+2016/2017+2017/2018+2018/2015 A=2015/2016+2016/2017+2017/2018+2018/2015 A=2016−1/2016+2017−1/2017+2018−1/2018+2015+3/2015 A=2016-12016+2017-12017+2018-12018+2015+32015 A=1−1/2016+1−1/2017+1−1/2018+1+3/2015 A=1-1/2016+1-1/2017+1-1/2018+1+3/2015 A=4+(1/2015−1/2016)+(1/2015−1/2017)+(1/2015−1/2018) A=4+(1/2015-1/2016)+(1/2015-1/2017)+(1/2015-1/2018) A=4+2016−2015/2015.2016+2017−2015/2015.2017+2018−2015/2015.2018 A=4+2016-20152015.2016+2017-20152015.2017+2018-20152015.2018 A=4+1/2015.2016+2/2015.2017+3/2015.2018 A=4+1/2015.2016+2/2015.2017+3/2015.2018 A>4+0+0+0=4 Trả lời
Đáp án:
Giải thích các bước giải:
`A=\frac{2015}{2016}+\frac{2016}{2017}+\frac{2017}{2018}+\frac{2018}{2015}`
`=\frac{2016-1}{2016}+\frac{2017-1}{2017}+\frac{2018-1}{2018}+\frac{2015+3}{2015}`
`=1-\frac{1}{2016}+1-\frac{1}{2017}+1-\frac{1}{2018}+1+\frac{3}{2015}`
`=4+(\frac{1}{2015}-\frac{1}{2016})+(\frac{1}{2015}-\frac{1}{2017})+(\frac{1}{2015}-\frac{1}{2018})`
`=4+\frac{2016-2015}{2015.2016}+\frac{2017-2015}{2015.2017}+\frac{2018-2015}{2015.2018}`
`=4+\frac{1}{2015.2016}+\frac{2}{2015.2017}+\frac{3}{2015.2018}`
`>4+0+0+0=4(đpcm)`
Đáp án:
A>4
Giải thích các bước giải:
A=2015/2016+2016/2017+2017/2018+2018/2015
A=2015/2016+2016/2017+2017/2018+2018/2015
A=2016−1/2016+2017−1/2017+2018−1/2018+2015+3/2015
A=2016-12016+2017-12017+2018-12018+2015+32015
A=1−1/2016+1−1/2017+1−1/2018+1+3/2015
A=1-1/2016+1-1/2017+1-1/2018+1+3/2015
A=4+(1/2015−1/2016)+(1/2015−1/2017)+(1/2015−1/2018)
A=4+(1/2015-1/2016)+(1/2015-1/2017)+(1/2015-1/2018)
A=4+2016−2015/2015.2016+2017−2015/2015.2017+2018−2015/2015.2018
A=4+2016-20152015.2016+2017-20152015.2017+2018-20152015.2018
A=4+1/2015.2016+2/2015.2017+3/2015.2018
A=4+1/2015.2016+2/2015.2017+3/2015.2018
A>4+0+0+0=4