Ôn tập toán 6
Các câu hỏi tương tự
Rút gọn
1.left(frac{2}{45}-frac{4}{13}-frac{1}{3}right):left(frac{3}{13}-frac{4}{15}+frac{2}{13}right)
2.frac{0,8:left(frac{4}{5}.1,25right)}{0,64-frac{1}{25}}+frac{left(1,08-frac{2}{15}right):frac{4}{7}}{left(6frac{5}{9}-3frac{1}{4}right)2frac{2}{17}}
3.frac{0,4-frac{2}{9}+frac{2}{11}}{1,4-frac{7}{9}+frac{7}{11}}-frac{frac{1}{3}-0,25+frac{1}{5}}{1frac{1}{6}-0,875+0,7}
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Rút gọn
1.\(\left(\frac{2}{45}-\frac{4}{13}-\frac{1}{3}\right):\left(\frac{3}{13}-\frac{4}{15}+\frac{2}{13}\right)\)
2.\(\frac{0,8:\left(\frac{4}{5}.1,25\right)}{0,64-\frac{1}{25}}+\frac{\left(1,08-\frac{2}{15}\right):\frac{4}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right)2\frac{2}{17}}\)
3.\(\frac{0,4-\frac{2}{9}+\frac{2}{11}}{1,4-\frac{7}{9}+\frac{7}{11}}-\frac{\frac{1}{3}-0,25+\frac{1}{5}}{1\frac{1}{6}-0,875+0,7}\)
Tính tổng :
a) Afrac{5}{2cdot1}+frac{4}{1cdot11}+frac{3}{11cdot14}+frac{1}{14cdot15}+frac{13}{15cdot28}
b) Bfrac{-1}{20}+frac{-1}{30}+frac{-1}{42}+frac{-1}{56}+frac{-1}{72}+frac{-1}{90}
c) Cfrac{1}{1cdot2cdot3}+frac{1}{2cdot3cdot4}+...+frac{1}{nleft(n+1right)left(n+2right)}
d) Dfrac{1}{1cdot2cdot3cdot4}+frac{1}{2cdot3cdot4cdot5}+...+frac{1}{nleft(n+1right)left(n+2right)left(n+3right)}
e) Eleft(frac{1}{1cdot2cdot3}+frac{1}{2cdot3cdot4}+...+frac{1}{37cdot38cdot39}right)cdot1482cdot185cdot8
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Tính tổng :
a) \(A=\frac{5}{2\cdot1}+\frac{4}{1\cdot11}+\frac{3}{11\cdot14}+\frac{1}{14\cdot15}+\frac{13}{15\cdot28}\)
b) \(B=\frac{-1}{20}+\frac{-1}{30}+\frac{-1}{42}+\frac{-1}{56}+\frac{-1}{72}+\frac{-1}{90}\)
c) \(C=\frac{1}{1\cdot2\cdot3}+\frac{1}{2\cdot3\cdot4}+...+\frac{1}{n\left(n+1\right)\left(n+2\right)}\)
d) \(D=\frac{1}{1\cdot2\cdot3\cdot4}+\frac{1}{2\cdot3\cdot4\cdot5}+...+\frac{1}{n\left(n+1\right)\left(n+2\right)\left(n+3\right)}\)
e) \(E=\left(\frac{1}{1\cdot2\cdot3}+\frac{1}{2\cdot3\cdot4}+...+\frac{1}{37\cdot38\cdot39}\right)\cdot1482\cdot185\cdot8\)
Rút gọn
1. \(\frac{5}{9}.\frac{7}{13}+\frac{5}{9}.\frac{9}{13}-\frac{5}{9}.\frac{3}{13}\)
2. \(\left(\frac{1+\frac{1}{5}+\frac{1}{7}+\frac{1}{11}}{2+\frac{2}{5}+\frac{2}{7}+\frac{2}{17}}:\frac{4-\frac{4}{7}+\frac{4}{9}-\frac{4}{13}}{1-\frac{1}{7}+\frac{1}{9}-\frac{1}{13}}\right):\frac{838383}{808080}\)
tính hợp lí ( nếu có thể )Bleft(frac{2}{3}-frac{1}{4}+frac{5}{11}right):left(frac{5}{12}+1-frac{7}{11}right)Cleft(-frac{14}{33}right).2frac{4}{9}+frac{48}{25}:frac{27}{25}Dleft(3-2frac{1}{3}+frac{1}{4}right):left(4-5frac{1}{6}+2frac{1}{4}right)Gleft(7frac{1}{9}-2frac{14}{15}right):left(2frac{2}{3}-6frac{2}{3}right)-frac{32}{45}H-frac{1}{7}.left(9frac{1}{2}-8,75right):frac{2}{7}+0,625:1frac{2}{3}
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tính hợp lí ( nếu có thể )
\(B=\left(\frac{2}{3}-\frac{1}{4}+\frac{5}{11}\right):\left(\frac{5}{12}+1-\frac{7}{11}\right)\)
\(C=\left(-\frac{14}{33}\right).2\frac{4}{9}+\frac{48}{25}:\frac{27}{25}\)
\(D=\left(3-2\frac{1}{3}+\frac{1}{4}\right):\left(4-5\frac{1}{6}+2\frac{1}{4}\right)\)
\(G=\left(7\frac{1}{9}-2\frac{14}{15}\right):\left(2\frac{2}{3}-6\frac{2}{3}\right)-\frac{32}{45}\)
\(H=-\frac{1}{7}.\left(9\frac{1}{2}-8,75\right):\frac{2}{7}+0,625:1\frac{2}{3}\)
Cho:
\(Q=\frac{5}{7}.\frac{13}{7^2}.\frac{97}{7^4}.....\frac{3^{2^{99}}+2^{2^{99}}}{7^{2^{99}}}\)
Chứng minh rằng: \(\left(Q.7^{2^{100}-1}\right)\in N\)
Cho:
\(Q=\frac{5}{7}.\frac{13}{7^2}.\frac{97}{7^4}.....\frac{3^{2^{99}}+2^{2^{99}}}{7^{2^{99}}}\)
Chứng minh rằng: \(Q\left(7^{2^{100}-1}\right)\in N\).
chứng minh rằng :
a) \(\frac{a}{n\left(n+a\right)}=\frac{1}{n}-\frac{1}{n+a}\) ( n , a ϵ N* )
b) áp dụng câu a tính ;
\(A=\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{99.100}\)
\(B=\frac{5}{1.4}+\frac{5}{4.7}+...+\frac{5}{100.103}\)
\(C=\frac{1}{15}+\frac{1}{35}+...+\frac{1}{2499}\)
Bài 1: a) Afrac{5}{11.16}+frac{5}{16.21}+frac{5}{21.26}+...+frac{5}{61.66} b) Bfrac{1}{2}+frac{1}{6}+frac{1}{12}+frac{1}{20}+frac{1}{30}+frac{1}{42} c) Cfrac{1}{1.2}+frac{1}{2.3}+...+frac{1}{1989.1990}Bài 2: a. Tính tổng: Mfrac{10}{56}+frac{10}{140}+frac{10}{260}+...+frac{10}{1400} b. Cho: Sfrac{3}{10}+frac{3}{11}+frac{3}{12}+frac{3}{13}+frac{3}{14} chứng minh rằng 1 S 2Bài 3: Tính giá trị của biểu thức sau:Aleft(frac{1}{7}+frac{1}{23}-frac{1}{1009}right):left(frac{1...
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Bài 1: a) \(A=\frac{5}{11.16}+\frac{5}{16.21}+\frac{5}{21.26}+...+\frac{5}{61.66}\)
b) \(B=\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\)
c) \(C=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{1989.1990}\)
Bài 2: a. Tính tổng: \(M=\frac{10}{56}+\frac{10}{140}+\frac{10}{260}+...+\frac{10}{1400}\)
b. Cho: \(S=\frac{3}{10}+\frac{3}{11}+\frac{3}{12}+\frac{3}{13}+\frac{3}{14}\) chứng minh rằng 1 < S < 2
Bài 3: Tính giá trị của biểu thức sau:
\(A=\left(\frac{1}{7}+\frac{1}{23}-\frac{1}{1009}\right):\left(\frac{1}{23}+\frac{1}{7}-\frac{2}{2009}+\frac{1}{7}.\frac{1}{23}.\frac{1}{2009}\right)+1:\left(30.1009-160\right)\)
Bài 4: Tính nhanh:
\(\text{a) 35 . 34 + 35 . 86 + 67 . 75 + 65 . 45}\)
\(\text{b) 21 . }7^2-11.7^2+90.7^2+49.125.16\)
Bài 5: Thực hiện phép tinh sau:
a. \(\frac{2181.729+243.81.27}{3^2.9^2.234+18.54+162.9+723.729}\)
b. \(\frac{1}{1.2+}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{98.99}+\frac{1}{99.100}\)
c. \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{100^2}< 1\)
d. \(\frac{5.4^{15}-9^9-4.3^{20}}{5.2^{19}.6^{19}-7.2^{29}.27^6}\)
giúp mk nha! nhớ viết cách làm nha!
thực hiện phép tính( tính nhanh nếu có thể)
a/ \(\frac{-7}{25}.\frac{11}{13}+\frac{-7}{25}.\frac{2}{13}-\frac{18}{25}\)
b/ \(\frac{5}{7}.\frac{1}{3}-\frac{5}{7}.\frac{1}{4}-\frac{5}{7}.\frac{1}{12}\)
c/ \(5\frac{2}{5}.4\frac{2}{7}+5\frac{5}{7}.5\frac{2}{5}\)
d/ \(75\%-1\frac{1}{2}+0,5:\frac{5}{12}-\left(\frac{-1}{2}\right)^2\)