a)
\(54-6.\left(9+11\right)\\ =54-6.9-6.11\\ =54-54-66\\ =0-66\\ =-66\)
b)
\(\dfrac{2}{3}\cdot\dfrac{-3}{4}+\dfrac{2}{3}\cdot\dfrac{-1}{4}+1\dfrac{2}{3}\\ =\dfrac{2}{3}.\left(\dfrac{-3}{4}+\dfrac{-1}{4}\right)+1\dfrac{2}{3}\\ =\dfrac{2}{3}\cdot\left(-1\right)+1\dfrac{2}{3}\\ =\dfrac{-2}{3}+1\dfrac{2}{3}=1\)
Bài 1: Thực hiện phép tính (hợp lý nếu có thể)
\((6\dfrac{4}{9}+3\dfrac{7}{11})-4\dfrac{4}{9}\)
\(1\dfrac{1}{3}-2\dfrac{5}{6}-\dfrac{6}{11}+3:5\%\)
\(4\dfrac{3}{4}-0,37+\dfrac{1}{8}-1,28-2,5+3\dfrac{1}{12}\)
\(\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}.\dfrac{14}{11}\)
\(\dfrac{\left(2^3.5.7\right).\left(5^2.7^3\right)}{\left(2.5.7^2\right)^2}\)
Tính:
\(\dfrac{\dfrac{1}{3}-\dfrac{1}{5}-\dfrac{1}{7}}{\dfrac{2}{3}-\dfrac{2}{5}-\dfrac{2}{7}}\) + \(\dfrac{\dfrac{4}{7}-\dfrac{4}{9}+\dfrac{4}{11}}{\dfrac{3}{7}-\dfrac{1}{3}+\dfrac{9}{11}}\)=?
Thực hiện phép tính( hợp lí nếu có thể)
\(\dfrac{1}{2}+\dfrac{3}{4}-\left(\dfrac{3}{4}-\dfrac{4}{5}\right)\)
\(\dfrac{-3}{7}+\dfrac{3}{4}:\dfrac{3}{14}\)
\(5-\dfrac{7}{39}:\dfrac{7}{13}+\dfrac{8}{9}:4\)
\(1\dfrac{13}{15}.0,75-\left(\dfrac{11}{20}+25\%\right):\dfrac{7}{3}\)
\(\left(\dfrac{5}{12}:\dfrac{11}{6}+\dfrac{5}{12}:\dfrac{11}{5}\right)--\dfrac{7}{12}\)
làm nhanh cho mình nha!!!!Thank nhìu
1. Tính giá trị biểu thức:
M=\(1+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{100}}\)
2.Chứng tỏ rằng :
\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{100^2}< 1\)
3.So sánh
a, A=\(\dfrac{11^5+1}{11^6+1}\) ; B=\(\dfrac{11^6+1}{11^7+1}\)
b, M=\(\dfrac{15^{10}-1}{15^9+1}\) ; N=\(\dfrac{15^9-1}{15^{10}+1}\)
Bài 1 : Tính
a) A=\(\dfrac{\dfrac{1}{9}-\dfrac{1}{7}-\dfrac{1}{11}}{\dfrac{4}{9}-\dfrac{4}{7}-\dfrac{4}{11}}\)\(+\dfrac{0,6-\dfrac{3}{25}-\dfrac{3}{125}-\dfrac{3}{625}}{\dfrac{4}{5}-0,16-\dfrac{4}{125}-\dfrac{4}{625}}\)
b)B=\(\dfrac{8}{9}-\dfrac{1}{72}-\dfrac{1}{56}-\dfrac{1}{42}-...-\dfrac{1}{6}-\dfrac{1}{2}\)
c)C=\(\dfrac{1}{1.3}-\dfrac{1}{2.4}+\dfrac{1}{3.5}-\dfrac{1}{4.6}+\dfrac{1}{5.7}-\dfrac{1}{6.8}+\dfrac{1}{7.9}-\dfrac{1}{8.10}\)
1 tiếng nữa mình cần rồi giúp mình nhé !!!!!!!!!! Vạn lời tri ân
a) A= 11 \(\dfrac{3}{13}\)- ( 3\(\dfrac{4}{7}\)+ 6\(\dfrac{3}{13}\) )
b) B= ( 7\(\dfrac{4}{9}\) + 3\(\dfrac{8}{13}\) ) \(-5\dfrac{4}{9}\)
c) C= \(\dfrac{-2}{7}.\dfrac{5}{11}+\dfrac{-2}{7}.\dfrac{6}{11}+5\dfrac{4}{7}\)
d) D= \(0,7.1\dfrac{3}{5}.30.0,375.\dfrac{4}{7}\)
tính:
\(\dfrac{2}{5}x\dfrac{1}{3}-\dfrac{2}{15}:\dfrac{1}{5}+\dfrac{3}{5}x\dfrac{1}{3}\)
2)\(\left(3\dfrac{1}{3}+2,5\right):\left(3\dfrac{1}{6}-4\dfrac{1}{5}\right)-\dfrac{11}{31}\)
3)\(\left[6+\left(\dfrac{1}{2^{ }}\right)^3-\left|-\dfrac{1}{2}\right|\right]:\dfrac{3}{12}\)
4)\(\dfrac{18}{37}+\dfrac{8}{24}+\dfrac{19}{37}-1\dfrac{23}{24}+\dfrac{2}{3}\)
5) \(\left(-2\right)^3x\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)
6)\(\left(\dfrac{2}{5}\right)^2+5\dfrac{1}{2}x\left(45-2\right)+\dfrac{23}{-4}\)
7)\(\dfrac{4}{9}-19\dfrac{1}{3}-\dfrac{4}{9}x39\dfrac{1}{3}\)
8)\(\left(-\dfrac{1}{2}\right)^2:\dfrac{1}{4}-2x\left(-\dfrac{1}{2}\right)^2\)
9)\(125\%x\left(-\dfrac{1}{2}\right)^3:\left(1\dfrac{5}{16}-1,5\right)+2008^0\)
giúp mình nha mai mình học rùi 
bài 1 : tính
a,\(\dfrac{-6}{11}\): (\(\dfrac{3}{5}.\)\(\dfrac{4}{11}\))
b, \(\dfrac{7}{12}\) + \(\dfrac{5}{12}\) : 6 - \(\dfrac{11}{36}\)
c, ( \(\dfrac{4}{5}\) +\(\dfrac{1}{2}\) ) : ( \(\dfrac{3}{13}\)-\(\dfrac{8}{13}\))
d, ( \(\dfrac{2}{3}\) -\(\dfrac{1}{4}\) +\(\dfrac{5}{11}\) ) : ( \(\dfrac{8}{12}\) +1 - \(\dfrac{7}{11}\) )
bài 2 , tìm x, biết
a, \(\dfrac{-2}{5}\). x +\(\dfrac{4}{3}\) = \(\dfrac{7}{3}\)
b,\(\dfrac{9}{8}\)+\(\dfrac{3}{8}\)-x = 0,125
c,\(\dfrac{3}{4}\): x =\(\dfrac{-7}{12}\)
d,\(\dfrac{3}{8}\)-\(\dfrac{1}{6}\)- x = \(\dfrac{1}{4}\)
e, \(\dfrac{1}{3}\)+\(\dfrac{1}{2}\): x = -4
thực hiện phép tính
d) \(\dfrac{-5}{9}+\dfrac{3}{5}-\dfrac{3}{9}+\dfrac{-2}{5}\) c) \(\left(\dfrac{1}{9}-\dfrac{9}{17}\right)+\dfrac{3}{6}-\left(\dfrac{12}{17}-\dfrac{1}{2}\right)+\dfrac{5}{9}\)
help me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
