\(A=\dfrac{7}{38}\left(\dfrac{9}{11}+\dfrac{4}{11}-\dfrac{2}{11}\right)=\dfrac{7}{38}\cdot1=\dfrac{7}{38}\)
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Đại số lớp 7
Các câu hỏi tương tự
B1
(-1/2)-(-3/5)+(-1/9)+1/131-(-2/7)+4/35-7/18
B2
A=1/3-3/5+5/7-7/9+9/11-11/13+13/15+11/13-9/11+7/9-5/7+3/5-1/3
B=1/99-1/99.98-1/98.97-1/97.96-...-1/3.2-1/2.1
A= 0,75-0,6+3/7+3/13 / 2,75-2,2+11/7=11/13
So sánh A và B biết : a, A=-2 /2011 -3/112 -5/113 - 7/114 ; B=-1/2011 -7/112 -5/113 - 3/114
b, A= 2006/2007 - 2007/2008 + 2008 / 2009 -2009/2010 B=1/2006.2007 -1/2008.2009
P=0.75=0.6+3/7+3/13 trên 2.75=2.2+11/7+11/13
a) dfrac{1}{3}-dfrac{3}{5}+dfrac{5}{7}-dfrac{7}{9}+dfrac{9}{11}-dfrac{11}{13}+dfrac{13}{15}+dfrac{11}{13}-dfrac{9}{11}+dfrac{7}{9}-dfrac{5}{7}+dfrac{3}{5}-dfrac{1}{3}
b)dfrac{1}{99}-dfrac{1}{99.98}-dfrac{1}{98.97}-dfrac{1}{97.96}-.....-dfrac{1}{3.2}-dfrac{1}{2.1}
c) dfrac{1}{1.3}+dfrac{1}{3.5}+.....+dfrac{1}{left(2n-1right)left(2n+1right)}+......+dfrac{1}{255.257}
Đọc tiếp
a) \(\dfrac{1}{3}-\dfrac{3}{5}+\dfrac{5}{7}-\dfrac{7}{9}+\dfrac{9}{11}-\dfrac{11}{13}+\dfrac{13}{15}+\dfrac{11}{13}-\dfrac{9}{11}+\dfrac{7}{9}\)\(-\dfrac{5}{7}+\dfrac{3}{5}-\dfrac{1}{3}\)
b)\(\dfrac{1}{99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-\dfrac{1}{97.96}-.....-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
c) \(\dfrac{1}{1.3}+\dfrac{1}{3.5}+.....+\dfrac{1}{\left(2n-1\right)\left(2n+1\right)}+......+\dfrac{1}{255.257}\)
a. -6.(-2/3).0,25b. -15/4.(-7/15).(-2 2/25)c. (-2 1/5).(-9/11).(-11/14).2/5Giúp mình!
Đọc tiếp
a. -6.(-2/3).0,25
b. -15/4.(-7/15).(-2 2/25)
c. (-2 1/5).(-9/11).(-11/14).2/5
Giúp mình!
27 Tính
A= \(\dfrac{10\dfrac{1}{3}.(26\dfrac{1}{3}-\dfrac{176}{7})-\dfrac{12}{11}.(\dfrac{10}{3}-1,75}{(\dfrac{5}{91-0,25)}.\dfrac{60}{11}-1}\)
\(\dfrac{\dfrac{3}{4}-\dfrac{3}{5}+\dfrac{3}{7}+\dfrac{3}{11}}{\dfrac{13}{4}-\dfrac{13}{5}+\dfrac{13}{7}+\dfrac{13}{11}}\)
Chứng minh : \(7^6+7^5-7^4⋮11\)