tinh hop li\(\frac{2011\cdot2010-1}{2009\cdot2011\cdot2010}\)
Những câu hỏi liên quan
TÍNH BẰNG CÁCH HỢP LÝ:
\(\frac{2011\cdot2010-1}{2009\cdot2011+2010}\)
\(\frac{2011.2010-1}{2009.2011+2010}=\frac{2011.\left(2009+1\right)-1}{2009.2011+2010}\)
\(=\frac{2011.2009+2011-1}{2009.2011+2010}\)
\(=\frac{2011.2009+2010}{2009.2011+2010}\)
\(=1\)
Nhớ k vs kp với mik nhé,mấy man!
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2011×2010-1
2009×2011+2010
Xem thêm câu trả lời
\(\frac{2008+2009\cdot2010}{2010\cdot2011-2012}\)
\(=\frac{2008+2009.2010}{2010.\left(2009+2\right)-2012}\)
\(=\frac{2009.2010+2008}{2010.2009+2010.2-2012}\)
\(=\frac{2008+2009.2010}{2008+2009.2010}=1\)
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1.tính nhanh
\(\dfrac{2009\cdot2010+2000}{2011\cdot2010+2020}\)
\(=\dfrac{2019.2010+1,005.2010}{2011.2010+2.2010}=\dfrac{2010\left(2019+1,005\right)}{2010\cdot\left(2011+2\right)}\)
\(=\dfrac{2020,005}{2013}=\dfrac{2020005}{2013000}=\dfrac{404001}{402600}\)
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Rút gọn biểu thức sau:
\(\frac{\text{(20082 - 2014)*(20082 + 4016 - 3)*2009}}{2005\cdot2007\cdot2010\cdot2011}\)
so sánh:
\(\frac{2}{1\cdot2\cdot3}+\frac{2}{2\cdot3\cdot4}+\frac{2}{3\cdot4\cdot5}+...+\frac{2}{2009\cdot2010\cdot2011}\)và\(\frac{1}{2}\)
2/1*2*3+2/3*4*5+...+2/2009*2010*2011
A=2/2*(1/1-1/2-1/3+1/2-1/3-1/4+1/4-1/5-1/6+...+1/2009-1/2010-1/2011
A=1*(1-1/2011)
A=1*2010/2011=2010/2011
suy ra: 2010/2011<1
suy ra 1/2 của 1 lớn hơn 2010/2011
VẬY A NHỎ HƠN 1/2
VẬY
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\(\frac{2009\cdot2010-1000}{2011\cdot2009-1009}\)
= 2009 * ( 2011 - 1 ) - 1000 / 2011 * 2009 - 1009
= 2009 * 2011 - 2009 -1000 / 2011 * 2009 - 1009
= 2009 * 2011 - 1009 / 2011 * 2009 - 1009
= 1
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tính bằng cách hợp lý:
\(\frac{2011\cdot2010-1}{2009\cdot1011+2010}\)
\(\frac{2011\cdot2010-1}{2009\cdot2011+2010}=\frac{2011\cdot\left(2009+1\right)-1}{2009\cdot2011+2010}=\frac{2011\cdot2009+2011\cdot1-1}{2009\cdot2011+2010}=\frac{ }{ }\)\(\frac{2011\cdot2009+2011-1}{2009\cdot2011+2010}=\frac{2011\cdot2009+2010}{2009\cdot2011+2010}=1\)
Tính nhanh :
\(\frac{2010\cdot2011+1000}{2012\cdot2010-1010}\)
\(\frac{2010\cdot2011+1000}{2012\cdot2010-1010}\)
= \(\frac{2010\cdot2011+1000}{\left(2011+1\right)\cdot2010-1010}\)
= \(\frac{2010\cdot2011+1000}{2011\cdot2010+2010-1010}\)
= \(\frac{2010\cdot2011+1000}{2011\cdot2010+1000}\)
= 1
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\(\frac{2010.2011+1000}{2012.2010-1010}\)
\(=\frac{2010.2011+2010-1010}{2012.2010-1010}\)
\(=\frac{2010.\left(2011+1\right)-1010}{2012.2010-1010}\)
\(=\frac{2010.2012-1010}{2012.2010-1010}\)
\(=1\)
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\(\frac{2010\cdot2011+1000}{2012\cdot2010-1010}\)= \(\frac{2010\cdot2011+1000}{2011\cdot2010+2010-1010}\)= \(\frac{2010\cdot2011+1000}{2011\cdot2010+1000}\)= 1
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Bài 1a) Tìm x, biết frac{2cdot x-4,36}{0,125} 0,25 * 42,9 - 11,7 * 0,25 + 0,25 * 0,8b) Tính nhanhNfrac{1}{1cdot5}+frac{1}{5cdot10}+frac{1}{10cdot15}+frac{1}{15cdot20}+...+frac{1}{2005cdot2010}Bài 2a) Tìm x, biết (x + 5,2) : 3,2 4,7 (dư 0,5).b) Tính nhanh:Afrac{4047991-2010cdot2009}{4050000-2011cdot2009}Bài 3a) Tìm x, biết 104,5 x X - 14,1 × X + 9,6 x X 25b) Tính nhanhTfrac{2009cdot2010+2000}{2011cdot2010-2020}
Đọc tiếp
Bài 1
a) Tìm x, biết
\(\frac{2\cdot x-4,36}{0,125}\)= 0,25 * 42,9 - 11,7 * 0,25 + 0,25 * 0,8
b) Tính nhanh
\(N=\frac{1}{1\cdot5}+\frac{1}{5\cdot10}+\frac{1}{10\cdot15}+\frac{1}{15\cdot20}+...+\frac{1}{2005\cdot2010}\)
Bài 2
a) Tìm x, biết (x + 5,2) : 3,2 = 4,7 (dư 0,5).
b) Tính nhanh:\(A=\frac{4047991-2010\cdot2009}{4050000-2011\cdot2009}\)
Bài 3
a) Tìm x, biết 104,5 x X - 14,1 × X + 9,6 x X = 25
b) Tính nhanh
\(T=\frac{2009\cdot2010+2000}{2011\cdot2010-2020}\)
\(\frac{2x-4,36}{0,125}=0,25.42,9-11,7.0,25+0,25.0,8\)
\(\Leftrightarrow\frac{2x-4,36}{0,125}=0,25.\left(42,9-11.7+0,8\right)\)
\(\Leftrightarrow\frac{2x-4,36}{0,125}=0,25.32\)
\(\Leftrightarrow\frac{2x-4,36}{0,125}=8\)
\(\Leftrightarrow2x-4,36=1\)
\(\Leftrightarrow2x=5,36\)
\(\Leftrightarrow x=2,68\)
b) \(N=\frac{1}{1.5}+\frac{1}{5.10}+\frac{1}{10.15}+\frac{1}{15.20}+...+\frac{1}{2005.2010}\)
\(\Leftrightarrow N=\frac{1}{5}\left(1-\frac{1}{5}+\frac{1}{5}-\frac{1}{10}+\frac{1}{10}-\frac{1}{15}+\frac{1}{15}-\frac{1}{20}+...+\frac{1}{2005}-\frac{1}{2010}\right)\)
\(\Leftrightarrow N=\frac{1}{5}\left(1-\frac{1}{2010}\right)\)
\(\Leftrightarrow N=\frac{1}{5}.\frac{2009}{2010}=\frac{2009}{10050}\)
Bài 1:
a)\(\frac{2\cdot x-4,36}{0,125}=0,25\cdot42,9-11,7\cdot0,25+0,25\cdot0,8\)
\(\frac{2\cdot x-4,36}{0,125}=0,25\cdot\left(42,9-11,7+0,8\right)\)
\(\frac{2\cdot x-4,36}{0,125}=0,25\cdot32\)
\(\frac{2\cdot x-4,36}{0,125}=8\)
\(2\cdot x-4,36=8\cdot0,125\)
\(2\cdot x-4,36=1\)
\(2\cdot x=1+4,36\)
\(2\cdot x=5,36\)
\(x=\frac{5,36}{2}=2,68\)
b) \(N=\frac{1}{1\cdot5}+\frac{1}{5\cdot10}+\frac{1}{10\cdot15}+\frac{1}{15\cdot20}+...+\frac{1}{2005\cdot2010}\)
\(4N=\frac{4}{1\cdot5}+\frac{4}{5\cdot10}+\frac{4}{10\cdot15}+\frac{4}{15\cdot20}+...+\frac{4}{2005\cdot2010}\)
\(4N=1-\frac{1}{5}+\frac{1}{5}-\frac{1}{10}+\frac{1}{10}-\frac{1}{15}+\frac{1}{15}-\frac{1}{20}+...+\frac{1}{2005}-\frac{1}{2010}\)
\(4N=1-\frac{1}{2010}=\frac{2009}{2010}\)
\(N=\frac{2009}{2010}\div4=\frac{2009}{8040}\)
Bài 2:
a) ( x + 5,2 ) : 3,2 = 4,7 ( dư 0,5 )
\(x+5,2=4,7\cdot3,2+0,5\)
\(x+5,2=15,54\)
\(x=15,54-5,2=10,34\)
b)\(A=\frac{4047991-2010\cdot2009}{4050000-2011\cdot2009}\)
\(A=\frac{4047991-2010\cdot2009}{4050000-2009-2010\cdot2009}\)
\(A=\frac{4047991-2010\cdot2009}{4047991-2010\cdot2009}=1\)
Bài 3:
a) \(104,5\cdot x-14,1\cdot x+9,6\cdot x=25\)
\(x\cdot\left(104,5-14,1+9,6\right)=25\)
\(x\cdot100=25\)
\(x=\frac{25}{100}=\frac{1}{4}=0,25\)
b) \(T=\frac{2009\cdot2010+2000}{2011\cdot2010-2020}\)
\(T=\frac{2009\cdot2010+2000}{2009\cdot2010+4020-2020}\)
\(T=\frac{2009\cdot2010+2000}{2009\cdot2010+2000}=1\)