Ta có:
\(\dfrac{637.527-189}{526.637+448}=\dfrac{637.\left(526+1\right)-189}{526.637+448}=\dfrac{637.526+637-189}{526.637+448}=\dfrac{637.526+448}{526.637+448}=1\)
Tính : \(\dfrac{15}{28}\)-\(\dfrac{186}{1116}\)-\(\dfrac{121}{462}\)+\(\dfrac{198}{189}\)
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 :
\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{10^2}\)\(< 1\)
Tính :
a) b)
\(\dfrac{\dfrac{5}{7}+\dfrac{5}{9}+\dfrac{5}{11}}{\dfrac{25}{7}+\dfrac{25}{7}+\dfrac{25}{11}}\) \(\dfrac{4+\dfrac{4}{73}-\dfrac{4}{115}}{5+\dfrac{5}{73}-\dfrac{1}{23}}\)
Mong mọi người sẽ trả lời nhanh ai nhanh mình sẽ cho 2 like luôn
Tinh nhanh
\(\dfrac{5}{12}+\dfrac{5}{20}+\dfrac{5}{30}+\dfrac{5}{42}+\dfrac{5}{56}\)
\(\dfrac{1}{6}+\dfrac{1}{10}+\dfrac{1}{15}+\dfrac{1}{21}+\dfrac{1}{28}+\dfrac{1}{36}+\dfrac{1}{45}\)
ai nhanh mk like cho
Tính nhanh:
\(A=\dfrac{1}{10}+\dfrac{1}{15}+\dfrac{1}{21}+...+\dfrac{1}{55}+\dfrac{1}{66}\)
tính nhanh:
\(-\dfrac{5}{12}.\dfrac{2}{7}+\dfrac{7}{12}-\dfrac{3}{14}\)
Tính nhanh
1) \(\dfrac{17}{5}.\dfrac{-31}{125}.\dfrac{1}{2}.\dfrac{10}{17}.\dfrac{-1}{2^3}\)
Tính nhanh:
\(B=\dfrac{1}{19}+\dfrac{9}{19.29}+\dfrac{9}{29.39}+...+\dfrac{9}{1999.2009}\)