Tính :
a) \(\frac{16.17-5}{16.16+11}\)
b) \(\frac{5}{30}+\frac{15}{90}+\frac{25}{150}+\frac{35}{210}+\frac{45}{270}\)
Những câu hỏi liên quan
Tính nhanh:
a)\(\frac{5}{30}+\frac{15}{90}+\frac{25}{150}+\frac{35}{210}+\frac{45}{270}\)
b)\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{56}\)
c)\(\frac{1}{15}+\frac{4}{30}+\frac{2}{45}+\frac{16}{60}+\frac{25}{75}+\frac{36}{90}+\frac{49}{105}+\frac{64}{120}+\frac{81}{135}\)
a) 5/30+15/90+25/150+35/210+45/270
=1/6+1/6+1/6+1/6+1/6
=1/6 x 5
=5/6
b) 1/2+1/6+1/12+1/20+....+1/56
=1/1x2+1/2x3+1/3x4+1/4x5+.....1/7x8
=1/1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+.......-1/7+1/7-1/8
=1/1-1/8
=7/8
c) mình chịu
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chịu,khó quá,nhất là câu c ý
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a,\(\frac{2}{3}\cdot\left(\frac{1}{3}+\frac{2}{5}\right)\)
b,24+25+26+.....+99+100
c,\(\frac{16\cdot17-5}{16\cdot16+11}\)
d,\(\frac{5}{80}+\frac{5}{90}+\frac{5}{150}+\frac{5}{210}+\frac{5}{270}\)
a) \(\frac{2}{3}.\left(\frac{1}{3}+\frac{2}{5}\right)=\frac{2}{3}.\frac{11}{15}=\frac{22}{45}\)
b) 24+25+26+...+99+100
= (100+24).77:2
= 124.77:2
= 4774
c) \(\frac{16.17-5}{16.16+11}=\frac{16.16+(16-5)}{16.16+11}=\frac{16.16+11}{16.16+11}=1\)
d) \(\frac{5}{80}+\frac{5}{90}+\frac{5}{150}+\frac{5}{210}+\frac{5}{270}\)
\(=\frac{1}{16}+\frac{1}{18}+\frac{1}{30}+\frac{1}{42}+\frac{1}{54}\)
\(=\frac{2929}{15120}\)
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a)=\(\frac{2}{3}.\left(\frac{5}{15}+\frac{6}{15}\right)\)
= \(\frac{2}{3}.\frac{11}{15}=\frac{22}{45}\)
d) = 5.(\(\frac{1}{80}+\frac{1}{90}+\frac{1}{150}+\frac{1}{210}+\frac{1}{270}\))
= 50........
kq là tự tính:)))))
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Tính hợp lý:
a)(56.27+56.35):62
b)\(3\frac{2}{7}.12\frac{1}{2}-3\frac{2}{7}.5\frac{1}{2}+1\frac{1}{2}:\frac{3}{4}\)
c)\(\frac{16.17-5}{16.16+11}\)
a) \(\left(56.27+56.35\right):62\)
\(=56.\left(27+35\right):62\)
\(=56.62:62\)
\(=56\)
b) \(3\frac{2}{7}.12\frac{1}{2}-3\frac{2}{7}.5\frac{1}{2}+1\frac{1}{2}:\frac{3}{4}\)
\(=3\frac{2}{7}.\left(12\frac{1}{2}-5\frac{1}{2}\right)+\frac{3}{2}.\frac{4}{3}\)
\(=\frac{23}{7}.7+2\)
\(=23+2\)
\(=25\)
c) \(\frac{16.17-5}{16.16+11}\)
\(=\frac{16.\left(16+1\right)-5}{16.16+11}\)
\(=\frac{16.16+16-5}{16.16+11}\)
\(=\frac{16.16+11}{16.16+11}\)
\(=1\)
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\(\frac{1}{5}+\frac{4}{10}+\frac{9}{15}+\frac{16}{20}+\frac{25}{25}+\frac{36}{30}+\frac{49}{35}+\frac{64}{40}+\frac{81}{45}\)=?
\(\frac{1}{5}+\frac{4}{10}+...+\frac{81}{45}=\frac{1}{5}+\frac{2}{5}+\frac{3}{5}+...+\frac{9}{5}=\frac{1+2+3+...+9}{5}=\frac{45}{5}=9\)
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1/5 + 4/10 + 9/15 + 16/20 + 25/25 + 36/30 + 49/35 + 64/40 + 81/45
=1/5 + 2/5 + 3/5 + 4/5 + 5/5 + 6/5 + 7/5 + 8/5 + 9/5
=45/5 = 9
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\(\frac{16.17-5}{16.16+11}\)
\(\frac{16.17-5}{16.16+11}\)
= \(\frac{16.\left(16+1\right)-5}{16.16}\)
= \(\frac{16.16+16-5}{16.16+11}\)
= \(\frac{16.16+11}{16.16+11}\)
= \(1\)
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\(\frac{16.17-5}{16.16+11}=\frac{17-5}{16+11}=\frac{8}{27}\)
Hok tốt ~~
K chắc đâu
# DanLinh
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\(\frac{16.17-5}{16.16+11}\)
= \(\frac{16.\left(16+1\right)-5}{16.16+11}\)
=\(\frac{16.16+16-5}{16.16+11}\) ( nhân tử chung )
= \(\frac{11}{11}\)
=1
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tính:\(A=1-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}+\frac{19}{90}\)
=\(\frac{3}{5}\)nha bạn nhớ k nha
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Tính tổng A= 1-\(\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}+\frac{19}{90}\)
Tính nhanh:
A=\(\frac{1}{90}-\frac{1}{72}-\frac{1}{56}-\frac{1}{42}-\frac{1}{30}-\frac{1}{20}-\frac{1}{12}-\frac{1}{6}-\frac{1}{2}\)
B=\(\frac{3}{2}-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}\)
A = \(\frac{-79}{90}\)
B = \(\frac{8}{9}\)
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tính nhanh
\(\frac{\left(456.11+912\right).37}{13.74}\)
\(\frac{864.48-432.96}{864.48.432}\)
\(\frac{16.17-5}{16.16+11}\)
\(\frac{45.16-17}{28+45.15}\)
\(\frac{7256.4375-725}{3650+4375.7255}\)
\(\frac{\left(456.11+912\right).37}{13.74}\)
\(=\frac{\left(456.11+456.2\right).37}{13.37.2}\)
\(=\frac{[456.\left(11+2\right).37}{13.37.2}\)
\(=\frac{456.13}{13.2}\)
\(=\frac{456}{2}=228\)
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