1/2 x 2/3
= 1 x 2 / 2 x 3 = 2/6 = 1/3
đ/s : 1/3
nha
\(\frac{1}{2}x\frac{2}{3}=\frac{1x2}{2x3}=\frac{2}{6}=\frac{1}{3}\)
\(\frac{1}{2}\times\frac{2}{3}\)
\(=\frac{3}{6}\times\frac{4}{6}\)
\(=\frac{12}{36}\)
\(=\frac{1}{3}\)
1/2 x 2/3
= 1 x 2 / 2 x 3 = 2/6 = 1/3
đ/s : 1/3
nha
\(\frac{1}{2}x\frac{2}{3}=\frac{1x2}{2x3}=\frac{2}{6}=\frac{1}{3}\)
\(\frac{1}{2}\times\frac{2}{3}\)
\(=\frac{3}{6}\times\frac{4}{6}\)
\(=\frac{12}{36}\)
\(=\frac{1}{3}\)
Tính nhanh:\(\frac{1}{2}\times\frac{1}{2}+\frac{1}{2}\times\frac{1}{3}+\frac{1}{3}\times\frac{1}{4}+\frac{1}{4}\times\frac{1}{5}+\frac{1}{5}\times\frac{1}{6}\)
\(\frac{1}{1}\times\frac{1}{2}+\frac{1}{2}\times\frac{1}{3}+\frac{1}{3}\times\frac{1}{4}+\frac{1}{4}\times\frac{1}{5}+\frac{1}{5}\times\frac{1}{6}\)
1.Tính nhanh
a,\(\frac{1}{1\times4}+\frac{1}{4\times7}+............+\frac{1}{97\times100}\)
b,\(\frac{1}{2}\times\frac{2}{3}\times\frac{3}{4}\times...........\times\frac{99}{100}\)
c,\(\frac{3}{4}\times\frac{8}{9}\times\frac{15}{16}\times...........\times\frac{99}{100}\)
d,\(\left(\frac{1}{2}+1\right)\times\left(\frac{1}{3}+1\right)\times\left(\frac{1}{4}+1\right)\times............\times\left(\frac{1}{99}+1\right)\)
e,\(\left(1-\frac{1}{2}\right)\times\left(1-\frac{1}{3}\right)\times\left(1-\frac{1}{4}\right)\times..........\times\left(1-\frac{1}{100}\right)\)
tính bằng cách thuận tiện
a. \(\frac{1}{2}\times\frac{2}{3}\div\frac{4}{3}\times\frac{4}{5}\div\frac{6}{5}\times\frac{6}{7}\div\frac{7}{8}\times\frac{8}{9}\div\frac{10}{9}\)
b.\(\frac{27}{49}\times\frac{49}{50}\times\frac{15}{51}\times(\frac{5}{10}-\frac{1}{2})\)
Tính giá trị biểu thức:
\(A=\frac{\frac{16}{10}:\left(1\frac{3}{5}\times \frac{5}{4}\right)}{\frac{64}{100}-\frac{1}{25}}+\frac{\left(\frac{108}{100}-\frac{2}{25}\right):\frac{4}{7}}{\left(5\frac{5}{9}-2\frac{1}{4}\right)\times 2\frac{2}{17}}+\frac{3}{5}\times \frac{1}{2}:\frac{2}{5}\)
\(\frac{1}{2}\times\frac{1}{3}\times\frac{1}{4}\times...\times\frac{1995}{1996}\times\frac{1996}{1997}\)
Tính M , biết :
\(M=1+\frac{1}{2}\times\left(1+2\right)+\frac{1}{3}\times\left(1+2+3\right)+\frac{1}{4}\times\left(1+2+3+4\right)+...+\frac{1}{2016}\times\left(1+2+3+4+...+2015+2016\right).\)
Hỏi trong 2 biểu thức dưới đây , biểu thức nào chia hết cho 5000 ?
\(1\times2\times3\times...\times4999\times\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{4999}\right)\)
\(1+2+3+...+4999+\left(1\times\frac{1}{2}\times\frac{1}{3}\times...\times\frac{1}{4999}\right)\)
Tính giá trị biểu thức sau :
\(A=\frac{\frac{16}{10}:\left(1\frac{3}{5}\times \frac{5}{4}\right)}{\frac{64}{100}-\frac{1}{25}}+\frac{\left(\frac{108}{100}-\frac{2}{25}\right):\frac{4}{7}}{\left(5\frac{5}{9}-2\frac{1}{4}\right)\times 2\frac{2}{17}}+\frac{3}{5}\times \frac{1}{2}:\frac{2}{5}\)
Tìm x, biết:
\(\frac{1}{2}\times\frac{1}{3}\times\frac{1}{4}\times\frac{1}{5}\times\frac{1}{6}\times\left(x-1,010\right)=\frac{1}{360}-\frac{1}{720}\)