Tính nhanh
A = ( 1999/2011 - 2011/1999 ) - ( -12/1999 - 12/2011 )
B = 2/5 + [ 3/11 + (-2)/5 ]
Những câu hỏi liên quan
tìm x
a) (x+1/5)mũ 2 +17/25=26/25
b)-1 5/27 - (3x-7/9)mux3= -24/27
c) -2/7<x/3<11/4
tính nhanh
a)(1999/2011-2011/1999)-(-12/1999-12/2011)
b) 67/111+2/33-15/117).(1/3-1/4-1/12)
tính nhanh: ( phân tích rõ ràng nha, bài kiểm tra hk2 đó,please,mk sẽ like cho bài nào rõ ràng nhất )
a) -9/10*5/14*1/10*(-9/2)+1/7*(-9/10)
b)(1999/2011-2011/1999)-(-12/1999-12/2011)
A.-9/10*5/14*1/10*(-9/2)+1/7*(-9/10)
=-9/10*(5/14+1/7)*1/10*(-9/2)
=-9/10*1/2*1/10*(-9/2)
=-9/20*1/10*(-9/10)
=-9/200*-9/10
=81/2000
B. (1999/2011-2011/1999)-(-12/1999-12/2011)
=1999/2011-2011/1999+12/1999+12/2011
=(1999/2011+12/2011)-(2011/1999-12/1999)
= 1-1
=0
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Tính Nhanh:\(\frac{1999}{2011}-\frac{2011}{1999}-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
\(\frac{1999}{2011}-\frac{2011}{1999}-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
\(=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)
\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)-\frac{2011}{1999}+\frac{12}{1999}\)
\(=1-\left(\frac{2011}{1999}-\frac{12}{1999}\right)\)
\(=1-1\)
\(=0\)
NHÉ !!!!!!!
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Ta có : \(\frac{1999}{2011}-\frac{2011}{1999}-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
=\(\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)
=\(\left(\frac{1999}{2011}+\frac{12}{2011}\right)+\left(\frac{12}{1999}-\frac{2011}{1999}\right)\)
=1-1
=0
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\(A=\left\{\frac{1999}{2011}-\frac{2011}{1999}\right\}-\left\{\frac{-12}{1999}-\frac{12}{2011}\right\}\)
\(B=\frac{2}{5}+\left(\frac{3}{11}+\frac{-2}{5}\right)\)
\(C=\frac{-5}{7}.\frac{4}{13}+\frac{-5}{7}.\frac{9}{13}+\frac{-2}{7}\)
\(D=\frac{-9}{10}.\frac{5}{14}+\frac{1}{10}.\left(\frac{-9}{2}\right)+\frac{1}{7}.\left(\frac{-9}{10}\right)\)
1 tinh
a,5dfrac{4}{23}.27dfrac{3}{47}+4dfrac{3}{47}.left(-5dfrac{4}{23}right)
b,4.left(dfrac{-1}{2}right)^3+dfrac{3}{2}
c,left(dfrac{1999}{2011}-dfrac{2011}{1999}right)-left(dfrac{-12}{1999}-dfrac{12}{2011}right)
d,left(dfrac{-5}{11}+dfrac{7}{22}-dfrac{-4}{33}-dfrac{5}{44}right):left(dfrac{381}{22}-39dfrac{7}{22}right)
Đọc tiếp
1 tinh
a,\(5\dfrac{4}{23}.27\dfrac{3}{47}+4\dfrac{3}{47}.\left(-5\dfrac{4}{23}\right)\)
b,4.\(\left(\dfrac{-1}{2}\right)^3+\dfrac{3}{2}\)
c,\(\left(\dfrac{1999}{2011}-\dfrac{2011}{1999}\right)-\left(\dfrac{-12}{1999}-\dfrac{12}{2011}\right)\)
d,\(\left(\dfrac{-5}{11}+\dfrac{7}{22}-\dfrac{-4}{33}-\dfrac{5}{44}\right):\left(\dfrac{381}{22}-39\dfrac{7}{22}\right)\)
a) \(5\dfrac{4}{23}.27\dfrac{3}{47}+4\dfrac{3}{47}.\left(-5\dfrac{4}{23}\right)\)
\(=5\dfrac{4}{23}.27\dfrac{3}{47}+\left(-4\dfrac{3}{47}\right).5\dfrac{4}{23}\)
\(=5\dfrac{4}{23}.\left[27\dfrac{3}{47}+\left(-4\dfrac{3}{47}\right)\right]\)
\(=5\dfrac{4}{23}.\left(27\dfrac{3}{47}-4\dfrac{3}{27}\right)\)
\(=5\dfrac{4}{23}.23\)
\(=\dfrac{119}{23}.23\)
\(=\dfrac{119}{23}\)
b) \(4.\left(\dfrac{-1}{2}\right)^3+\dfrac{3}{2}\)
\(=4.\dfrac{-1}{6}+\dfrac{3}{2}\)
\(=\dfrac{-4}{6}+\dfrac{3}{2}\)
\(=\dfrac{-2}{3}+\dfrac{3}{2}\)
\(=\dfrac{-4}{6}+\dfrac{9}{6}\)
\(=\dfrac{5}{6}\)
c) \(\left(\dfrac{1999}{2011}-\dfrac{2011}{1999}\right)-\left(\dfrac{-12}{1999}-\dfrac{12}{2011}\right)\)
\(=\dfrac{1999}{2011}-\dfrac{2011}{1999}-\dfrac{-12}{1999}+\dfrac{12}{2011}\)
\(=\left(\dfrac{1999}{2011}+\dfrac{12}{2011}\right)-\left(\dfrac{2011}{1999}+\dfrac{-12}{1999}\right)\)
\(=\dfrac{2011}{2011}-\dfrac{1999}{1999}\)
\(=1-1\)
\(=0\)
d) \(\left(\dfrac{-5}{11}+\dfrac{7}{22}-\dfrac{-4}{33}-\dfrac{5}{44}\right):\left(\dfrac{381}{22}-39\dfrac{7}{22}\right)\)
(đợi đã, mình chưa tìm được hướng làm...)
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d) \(\left(\dfrac{-5}{11}+\dfrac{7}{22}-\dfrac{-4}{33}-\dfrac{5}{44}\right):\left(\dfrac{381}{22}-39\dfrac{7}{22}\right)\)
\(=\left(\dfrac{-60}{132}+\dfrac{42}{132}-\dfrac{-16}{132}-\dfrac{15}{132}\right):\left(\dfrac{381}{22}-39\dfrac{7}{22}\right)\)
\(=\dfrac{-17}{132}:\left(\dfrac{381}{22}-\dfrac{865}{22}\right)\)
\(=\dfrac{-17}{132}:\left(-22\right)\)
\(=\dfrac{-17}{132}.\dfrac{1}{-22}\)
\(=\dfrac{-17}{-2904}=\dfrac{17}{2904}\)
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Tính nhanh:
\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
\(=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)
\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)+\left(-\frac{2011}{1999}+\frac{12}{1999}\right)\)
\(=\frac{2011}{2011}+\frac{-1999}{1999}=1+\left(-1\right)=0\)
\(\frac{1999}{2011}-\frac{2011}{1999}-\left(\frac{-12}{1999}-\frac{12}{2011}\right)=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)
\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)-\left(\frac{2011}{1999}-\frac{12}{1999}\right)=1-1=0\)
\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
\(=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)
\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)+\left(\frac{-2011}{1999}+\frac{12}{1999}\right)\)
\(=1-1\)
\(=0\)
Học tốt
Tinh nhanh
(1999/2011-2011/1999)-(-12/1999-12/2011)
(1999/2011-2011/1999) - (-12/1999 - 12/2011)
= 1999/2011 - 2011/1999 + 12/1999 + 12/2011
= (1999/2011 + 12/2011) - 1999/1999 - 12/1999 + 12/1999
= ( 1-1 ) + ( -12/1999 + 12/1999)
= 0 + 0
= 0
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(1999/2011-2011/1999)-(12/1999-12/2011)
=1999/2011-2011/1999-12/1999+12/2011
=(1999/2011+12/2011)-(2011/1999-12/1999)
=1-1
=0
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tính nhanh (1999/2011-2011/1999)-(-12/1999-12/2011)
làm giúp mình nha cảm ơn
các bạn giải chi tiết ra nhé
kết quả là 0 nhé
Tính nhanh: \(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)
\(=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)
\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)+\left(\frac{-2011}{1999}+\frac{12}{1999}\right)=\frac{2011}{2011}-\frac{1999}{1999}=1-1=0\)
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\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(-\frac{12}{1999}-\frac{12}{2011}\right)\)
\(=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)
\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)+\left(-\frac{2011}{1999}+\frac{12}{1999}\right)\)
\(=1+\left(-1\right)\)
\(=0\)
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\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(-\frac{12}{1999}-\frac{12}{2011}\right)=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}=\frac{1999}{2011}-1+\frac{12}{2011}=-\frac{12}{2011}+\frac{12}{2011}=0\)
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