\(\left(2013\cdot2014+2014\cdot2015+2015\cdot2016\right)\cdot\left(1+\frac{1}{3}-1\frac{1}{3}\right)\)
\(\left(2013.2014+2014.2015+2015.2016\right)\left(1+\frac{1}{3}-1\frac{1}{3}\right)\)
\(=\left(2013.2014+2014.2015+2015.2016\right)\left(\frac{4}{3}-\frac{4}{3}\right)\)
\(=\left(2013.2014+2014.2015+2015.2016\right).0\)
\(=0\)
Tính nhanh :
a) \(\frac{2015\cdot2017-1}{2014+2015\cdot2016}\)
b) \(\frac{1}{1\cdot5}+\frac{1}{5\cdot9}+...+\frac{1}{2011\cdot2015}\)
c)\(\frac{12}{35}+\frac{1212}{3535}+\frac{121212}{353535}+\frac{12121212}{35353535}\)
a,\(\frac{2015.2016+2015-1}{2014+2015.2016}=\frac{2015.2016+2014}{2014+2015.2016}=1\)\(1\)
b,\(=1-\frac{1}{5}+\frac{1}{5}...-\frac{1}{2011}+\frac{1}{2011}-\frac{1}{2015}=1-\frac{1}{2015}=\frac{2014}{2015}\)
c,\(=\frac{12}{35}+\frac{12}{35}+\frac{12}{35}+\frac{12}{35}=\frac{12}{35}.4=\frac{48}{35}\)
b>=1-1/5+1/5-1/9+...+1/2011-1/2015
=1-1/2015
=2014/2015
c>=12/35+12/35+12/35+12/35
=12/35x4
=48/35
a. \(A=0.1+0.2+.......+0.19\)
b. \(B=\left(2017\cdot2016+2014\cdot2015\right)\cdot\left(1+\frac{1}{2}:1\frac{1}{2}+1\frac{1}{3}\right)\)
a. ta có (0.1+0.19)+(0.2+0.18)......+0.10
A=0.20+0.20++0.20+0.20+0.20+0.20+0.20+0.20+0.20+0.10
A=1.90
câu b mình pó tay
a ) \(A=0,1+0,2+...+0,19\)
\(A=\left(0,1+0,2+...+0,9\right)+\left(0,10+0,11+...+0,19\right)\)
\(A=0,1\times\left(1+2+...+9\right)+0,1\times\left(1+1,1+...+1,9\right)\)
\(A=0,1\times45+0,1\times14,5\)
\(A=0,1\times\left(45+14,5\right)\)
\(A=0,1\times59,5\)
\(A=5,95\)
b ) \(B=\left(2017\times2016+2014\times2015\right)\times\left(1+\frac{1}{2}\div1\frac{1}{2}+1\frac{1}{3}\right)\)
\(B=\left(2017\times2016+2014\times2015\right)\times\left(1+\frac{1}{2}\div\frac{3}{2}+\frac{4}{3}\right)\)
\(B=\left(2017\times2016+2014\times2015\right)\times\left(1+\frac{2}{6}+\frac{4}{3}\right)\)
\(B=\left(2017\times2016+2014\times2015\right)\times\frac{8}{3}\)
Tính: C=\(2\frac{1}{2016}\cdot\frac{1}{2015}-\frac{1}{672}\cdot3\frac{2014}{2015}-\frac{4}{2014\cdot2015}+\frac{4}{672}\)
tính nhanh : \(\frac{2014\cdot2015+1014}{2014\cdot2016-1000}=?\)
Tử số = 2014x 2015 + 1014 = 2014 x 2015 + 2014 - 1000
Mẫu số = 2014 x 2016 -1000 = 2014 x ( 2015 +1) -1000 = 2014 x 2015 + 2014 -1000
Tử số / Mẫu số = 2014 x 2015 + 2014 - 1000 / 2014 x 2015 + 2014 -1000 =1
( Không viết được dạng phân số nên đành phải viết như thế kia nhé )
\(\frac{2012+2013\cdot2014}{2014\cdot2015+2016}\)
\(\frac{2012+2013.2015}{2014.2015+2016}=\frac{4056194}{4060226}\)
\(\frac{2012+2013\cdot2014}{2014\cdot2015-2016}\)
\(\frac{2012+2013\cdot2014}{2014\cdot2015-2016}\)
2012+2013.2014
2014.2015-2016
2012+2013.2014
2014.(2013+2)-2016
2012+2013.2014
2014.2013+4028-2016
2012
2012
\(\left(1+\frac{1}{2}+....+\frac{1}{5}\right)\cdot x+\frac{2014}{1}+\frac{2016}{2}+....+\frac{4025}{2012}+\frac{4027}{2014}\)
\(\cdot\)Là Dấu Nhân
