Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Ta có:
A = 2017 2018 + 2018 2019 > 2010 2011 + 2011 2012 = 2010 + 2011 2012 > 2010 + 2011 2011 + 2012 = B
Vậy A > B
Đáp án A
Ta có: 2011 2012 + 2012 2013 + 2013 2011 = 2012 - 1 2012 + 2013 - 1 2013 + 2011 + 1 + 1 2011
= 1 - 1 2012 + 1 - 1 2013 + 1 + 1 2011 + 1 + 1 2011
= 3 + 1 2011 - 1 2012 + 1 2011 - 1 2013
Ta thấy vì 2011 < 2012 < 2013 nên 1 2011 > 1 2012 > 1 2013
Suy ra: 1 2011 - 1 2012 > 0 ; 1 2011 - 1 2012 > 0
Do đó: 3 + 1 2011 - 1 2012 + 1 2011 - 1 2013 > 3
Hay . 2011 2012 + 2012 2013 + 2013 2011 > 3
Đáp án cần chọn là: A
b, \(\dfrac{56\cdot2+56\cdot3}{15\cdot56}=\dfrac{56\cdot\left(2+3\right)}{15\cdot56}\)
=\(\dfrac{56\cdot5}{15\cdot56}=\dfrac{1}{3}\)
c, \(\dfrac{20082008}{20112011}=\dfrac{2008\cdot10001}{2011\cdot10001}=\dfrac{2008}{2011}\)
d, \(\dfrac{2+2}{217\cdot32+217+33}=\dfrac{4}{217\cdot\left(32+33\right)}\)
=\(\dfrac{4}{217\cdot65}=\dfrac{4}{14105}\)
\(\frac{199.......9}{999.......5}=\frac{199.......9:199.......9}{999.......5:199........9}=\frac{1}{5}\)
\(\frac{121212}{424242}=\frac{121212:10101}{424242:10101}=\frac{12}{42}\)
\(\frac{187187187}{221221221}=\frac{187187187:1001001}{221221221:1001001}=\frac{187}{221}\)
\(\frac{20082008}{20112011}=\frac{20082008:10001}{20112011:10001}=\frac{2008}{2011}\)
\(\frac{199...9}{99...95}\)=\(\frac{199...9:199...9}{99...95:199...9}\)\(\frac{\left(20so9\right)}{\left(20so9\right)}\)
=\(\frac{1}{5}\)
20112012 - 20112011 = 20112011.(2011 - 1) = 20112011.2010
20112011 - 20112010 = 20112010.(2011 - 1) = 20112010.2010
Vì 20112011 > 20112010 nên 20112011.2010 > 20112010.2010
Vậy 20112012 - 20112011 > 20112011 - 20112010
bài làm
20112012 - 20112011
= 20112011.(2011 - 1)
= 20112011.2010
20112011 - 20112010
= 20112010.(2011 - 1)
= 20112010.2010
Do 20112011 > 20112010 nên 20112011.2010 > 20112010.2010
Vậy .....................
hok tốt