tính nhanh: 2016.(-2015+1) -2015 . (1-2016)
1,Tính nhanh
[2015*2015*2014-2014-2014*2015]*[2016*2016+2015*2015*2016]
Tính nhanh nếu có thể
a. 2017/2016 nhân 3/4 trừ 1/2016 nhân 0,75
b.1/2 nhân 2015/2016 cộng 1/3 nhân 2015/2016 trừ 2015/2016 nhân 5/6
a)\(=\frac{2017}{2016}.\frac{3}{4}-\frac{1}{2016}.\frac{3}{4}\)
\(=\frac{3}{4}\left(\frac{2017}{2016}-\frac{1}{2016}\right)\)
\(=\frac{3}{4}.1\)
\(=\frac{3}{4}\)
b)\(=\frac{2015}{2016}\left(\frac{1}{2}+\frac{1}{3}-\frac{5}{6}\right)\)
\(=\frac{2015}{2016}.0\)
\(=0\)
1 Tính nhanh
2015 - ( 403.5 - 2016) - 2016 + 2^2017 : 2^2015 - 2^2015:4^1007-1-3+4-5-6+11
=2015-(2015-2016)-2016+22017-2015-22015/22014-(1-4)-3-(5+6)+11
=(2015-2015)+(2016-2016)+22-2+3-3-11+11
=0+0+(4-2)+(3-3)-(11-11)
=2
Tính
(1/2 + 2015/2016 + 2016/2017 + 1)(2015/2016 + 2016/2017 + 7/22) - (1/2 + 2015/2016 + 2016/2017)(2015/2016 + 2016/2017 + 7/22 + 1)
(1+2015/2016+2016/2017+1/2).(2015/2016+2016/2017+7/22)-(2015/2016+2016/2017+1/2).(2015/2016+2016/2017+7/22+1)
tính tổng trên
( trình bày cách tính
Tính nhanh : \(\frac{2017+\frac{1}{2016}+\frac{2}{2015}+\frac{3}{2014}+...+\frac{2015}{2}+\frac{2016}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2015}+\frac{1}{2016}}\)
tính nhanh (2015+2014*2016)/(2015*2016-1)
ai nhanh mình k nhưng phải đúng và trình bày nha
\(\frac{2015+2014\cdot2016}{2015\cdot2016-1}\)
\(=\frac{2015+\left(2015-1\right)2016}{2015\cdot2016-1}\)
\(=\frac{2015-2016+2015\cdot2016}{2015\cdot2016-1}\)
\(=\frac{2015\cdot2016-1}{2015\cdot2016-1}\)
\(=1\)
Tính nhanh:
500.(4-124)-124.(-500) 2016.(-2015+1)-2015.(1-2016)=(-2015.2016+2016.1)-(2015.1-2015.2016)
=-2015.2016+2016-2015+2015.2016
=2016(-2015+2015)+(2016-2015)
=2016.0+1
=0+1
=1
2016.(-2015+1)-2015.(1-2016)=2016-2016.2015+2015.2016-2015=(2015.2016-2016.2015)+(2016-2015)=1
bài 2: Tính nhanh
a) A = 201^2
b) B= 498^2
c) C= 93. 107
d) D= 2016^2 - 2015. 2017
e) E= 2016^3 - 1
________
2016^2 + 2017
g) G= 2016^2 - 2015^2 + 2014^2 - 2013^2 + 2012^2 - 2011^2 + 2010^2 - 1^2
\(201^2=\left(200+1\right)^2=200^2+2.200.1+1^2=40000+400+1=40401\)
\(498^2=\left(500-2\right)^2=500^2-2.500.2+2^2=250000-2000+4=248004\)
\(93.107=\left(100-7\right)\left(100+7\right)=100^2-7^2=10000-49=9951\)
\(2016^2-2015.2017=2016^2-\left(2016-1\right)\left(2016+1\right)=2016^2-2016^2+1^2=1\)