Đại số lớp 6
Các câu hỏi tương tự
x+30/100.x= -1,31
(4,5-2x).(\(-1\dfrac{4}{7}\))=\(\dfrac{11}{4}\)
A=1+2+3+4+5+...+99+100
B=\(\dfrac{1}{2}\)+\(\dfrac{1}{6}\)+\(\dfrac{1}{12}\)+\(\dfrac{1}{20}\)+\(\dfrac{1}{30}\)+...+\(\dfrac{1}{9900}\)
Tính:
Q = \(\dfrac{1}{2}+\dfrac{5}{6}+\dfrac{11}{12}+\dfrac{19}{20}+\dfrac{29}{30}+\dfrac{41}{42}+\dfrac{55}{56}+\dfrac{71}{72}+\dfrac{89}{90}\)
BT2: Tính nhanh
9) \(\dfrac{98}{99}+\dfrac{89}{100}+\dfrac{100}{101}.\left(\dfrac{1}{12}-\dfrac{1}{3}+\dfrac{1}{4}\right)\)
10) \(\left(\dfrac{78}{79}+\dfrac{79}{80}+\dfrac{80}{81}\right).\left(\dfrac{1}{5}+\dfrac{1}{6}+\dfrac{3}{10}-\dfrac{2}{3}\right)\)
Giúp mk nha!
1. Tính nhanh :
dfrac{1}{6}+dfrac{1}{12}+dfrac{1}{20}+dfrac{1}{30}+dfrac{1}{42}+dfrac{1}{56}
2. Tính nhanh :
dfrac{1}{15}+dfrac{1}{35}+dfrac{1}{63}+dfrac{1}{99}+dfrac{1}{143}
3. Tính nhanh :
dfrac{1}{2}+dfrac{1}{14}+dfrac{1}{35}+dfrac{1}{65}+dfrac{1}{104}+dfrac{1}{152}
4. Chứng minh rằng :
dfrac{1}{2^2}+dfrac{1}{3^2}+dfrac{1}{4^2}+...+dfrac{1}{10^2} 1
Đọc tiếp
1. Tính nhanh :
\(\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}+\dfrac{1}{56}\)
2. Tính nhanh :
\(\dfrac{1}{15}+\dfrac{1}{35}+\dfrac{1}{63}+\dfrac{1}{99}+\dfrac{1}{143}\)
3. Tính nhanh :
\(\dfrac{1}{2}+\dfrac{1}{14}+\dfrac{1}{35}+\dfrac{1}{65}+\dfrac{1}{104}+\dfrac{1}{152}\)
4. Chứng minh rằng :
\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{10^2}\)\(< 1\)
Rút gọn
a) B=(\(1-\dfrac{1}{2}\))x\(\left(1-\dfrac{1}{3}\right)x\left(1-\dfrac{1}{4}\right)x....\left(1-\dfrac{1}{20}\right)\)
b) tính nhanh
P=\(\dfrac{\dfrac{2}{3}-\dfrac{1}{4}+\dfrac{5}{11}}{\dfrac{5}{12}+1-\dfrac{6}{11}}\)
Thực hiện phép tính( hợp lí nếu có thể)
dfrac{1}{2}+dfrac{3}{4}-left(dfrac{3}{4}-dfrac{4}{5}right)
dfrac{-3}{7}+dfrac{3}{4}:dfrac{3}{14}
5-dfrac{7}{39}:dfrac{7}{13}+dfrac{8}{9}:4
1dfrac{13}{15}.0,75-left(dfrac{11}{20}+25%right):dfrac{7}{3}
left(dfrac{5}{12}:dfrac{11}{6}+dfrac{5}{12}:dfrac{11}{5}right)--dfrac{7}{12}
làm nhanh cho mình nha!!!!Thank nhìu
Đọc tiếp
Thực hiện phép tính( hợp lí nếu có thể)
\(\dfrac{1}{2}+\dfrac{3}{4}-\left(\dfrac{3}{4}-\dfrac{4}{5}\right)\)
\(\dfrac{-3}{7}+\dfrac{3}{4}:\dfrac{3}{14}\)
\(5-\dfrac{7}{39}:\dfrac{7}{13}+\dfrac{8}{9}:4\)
\(1\dfrac{13}{15}.0,75-\left(\dfrac{11}{20}+25\%\right):\dfrac{7}{3}\)
\(\left(\dfrac{5}{12}:\dfrac{11}{6}+\dfrac{5}{12}:\dfrac{11}{5}\right)--\dfrac{7}{12}\)
làm nhanh cho mình nha!!!!Thank nhìu
Tính nhanh
a)(5dfrac{1}{7}- 3dfrac{3}{11}) - 2dfrac{1}{7}-1dfrac{8}{11}
b) (dfrac{1999}{2011}-dfrac{2011}{1999}) -(dfrac{-12}{1999}-dfrac{12}{2011})
c)(1-dfrac{1}{2})(1-dfrac{1}{3})............(1-dfrac{1}{2017})
d) dfrac{2}{15}.6dfrac{5}{11}+dfrac{5}{11}.dfrac{-2}{15}-dfrac{2}{15}.2015^0
e)dfrac{1}{6}-dfrac{1}{39}+dfrac{1}{51}:dfrac{1}{8}-dfrac{1}{12}+dfrac{1}{68}
Đọc tiếp
Tính nhanh
a)(5\(\dfrac{1}{7}\)- 3\(\dfrac{3}{11}\)) - 2\(\dfrac{1}{7}\)-1\(\dfrac{8}{11}\)
b) (\(\dfrac{1999}{2011}-\dfrac{2011}{1999}\)) -(\(\dfrac{-12}{1999}-\dfrac{12}{2011}\))
c)(1-\(\dfrac{1}{2}\))(1-\(\dfrac{1}{3}\))............(1-\(\dfrac{1}{2017}\))
d) \(\dfrac{2}{15}.6\dfrac{5}{11}+\dfrac{5}{11}.\dfrac{-2}{15}\)\(-\dfrac{2}{15}.2015^0\)
e)\(\dfrac{1}{6}-\dfrac{1}{39}+\dfrac{1}{51}\):\(\dfrac{1}{8}-\dfrac{1}{12}+\dfrac{1}{68}\)
Cho S = \(\dfrac{1}{11}+\dfrac{1}{12}+\dfrac{1}{13}+\dfrac{1}{14}+\dfrac{1}{15}+\dfrac{1}{16}+\dfrac{1}{17}+\dfrac{1}{18}+\dfrac{1}{19}+\dfrac{1}{20}\). Hãy so sánh S và \(\dfrac{1}{2}\)
Chứng minh
1-dfrac{1}{2}+dfrac{1}{3}-dfrac{1}{4}+dfrac{1}{5}-dfrac{1}{6}+...+dfrac{1}{19}-dfrac{1}{20}dfrac{1}{11}+dfrac{1}{12}+dfrac{1}{13}+...+dfrac{1}{20}
help me
Đọc tiếp
Chứng minh
1-\(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)-\(\dfrac{1}{4}\)+\(\dfrac{1}{5}\)-\(\dfrac{1}{6}\)+...+\(\dfrac{1}{19}\)-\(\dfrac{1}{20}\)=\(\dfrac{1}{11}\)+\(\dfrac{1}{12}\)+\(\dfrac{1}{13}\)+...+\(\dfrac{1}{20}\)
help me