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\(=\frac{199.2000+199-1}{1998+1999.2000}.\frac{7}{5}\)
\(=\frac{199.2-1}{1998-1999}.\frac{7}{5}\)
\(=\frac{398-1}{-1}.\frac{7}{5}\)
\(=\frac{397}{-1}.\frac{7}{5}\)
\(=-397.\frac{7}{5}\)
\(=-555,8\)
Hình như sai đề
\(a,\left(16.23+16.77\right)-\left(5.30-5.20\right)\)
\(=16.\left(23+77\right)-5.\left(30-20\right)\)
\(=16.100-5.10\)
\(=1600-50\)
\(=1550\)
\(b,8\frac{1}{2}\div\frac{17}{5}+\frac{6}{8}\div3\frac{2}{3}\)
\(=\frac{17}{2}.\frac{5}{17}+\frac{3}{4}\div\frac{11}{3}\)
\(=\frac{17}{2}.\frac{5}{17}+\frac{3}{4}.\frac{3}{11}\)
\(=\frac{5}{2}+\frac{9}{44}\)
\(=\frac{110}{44}+\frac{9}{44}\)
\(=\frac{119}{44}\)
\(a,=16.100-5.10=1600-50=1550\)
\(b,8\frac{1}{2}:\frac{17}{5}+\frac{6}{8}:3\frac{2}{3}=\frac{17}{2}.\frac{5}{17}+\frac{6}{8}:\frac{11}{3}=\frac{5}{2}+\frac{18}{88}=\frac{220}{88}+\frac{18}{88}=\frac{238}{88}=2\frac{31}{44}\)
\(\frac{1999\cdot2001-1}{1998+1999\cdot2000}\cdot\frac{7}{5}\)
\(=\frac{1999\cdot\left(2000+1\right)-1}{1998+1999\cdot2000}\cdot\frac{7}{5}\)
\(=\frac{1999\cdot2000+1999-1}{1998+1999.2000}\cdot\frac{7}{5}\)
\(=\frac{1999\cdot2000+1998}{1998+1999.2000}\cdot\frac{7}{5}=1\cdot\frac{7}{5}=\frac{7}{5}\)
\(\frac{1}{8}=12,5\%\) ; \(\frac{1}{16}=6,25\%\) ; \(\frac{1}{2}=50\%\) ; \(\frac{1}{4}=25\%\)
Thay vào trên mà tính.
= \(1+\left(\frac{3\left(1x2+2x4x2\right)}{3\left(5+5x3x25\right)}+1\right)-\left(1+\frac{18}{54}\right)-1\) = \(\frac{18}{380}-\frac{18}{54}\)
14 : ( 4\(\frac{2}{3}\)- 1\(\frac{5}{9}\)) + 14 : ( \(\frac{2}{3}\)+ \(\frac{8}{9}\))
= 14 : ( \(\frac{14}{3}\)- \(\frac{14}{9}\)) + 14 : ( \(\frac{6}{9}\) + \(\frac{8}{9}\))
= 14 : ( 14 - \(\frac{14}{9}\)) + 14 : \(\frac{14}{9}\)
= 14 : \(\frac{112}{9}\)+ 14 : \(\frac{14}{9}\)
= \(\frac{9}{8}\)+ 9
= \(\frac{81}{8}\)
\(\frac{1}{11\times16}+\frac{1}{16\times21}+\frac{1}{21\times26}+...+\frac{1}{56\times61}+\frac{1}{61\times66}\)
\(=\frac{1}{5}\times\left(\frac{1}{11}-\frac{1}{16}+\frac{1}{16}-\frac{1}{21}+\frac{1}{21}-\frac{1}{26}+...+\frac{1}{56}-\frac{1}{61}+\frac{1}{61}-\frac{1}{66}\right)\)
\(=\frac{1}{5}\times\left(\frac{1}{11}-\frac{1}{66}\right)\)
\(=\frac{1}{5}\times\frac{5}{66}\)
\(=\frac{1}{66}\)
\(\frac{1}{11\times16}+\frac{1}{16\times21}+\frac{1}{21\times26}+...+\frac{1}{56\times61}+\frac{1}{61\times66}\)
\(=\frac{1}{5}\times\left(\frac{5}{11\times16}+\frac{5}{16\times21}+\frac{5}{21\times26}+...+\frac{5}{56\times61}+\frac{5}{61\times66}\right)\)
\(=\frac{1}{5}\times\left(\frac{1}{11}-\frac{1}{16}+\frac{1}{16}-\frac{1}{21}+\frac{1}{21}-\frac{1}{26}+...+\frac{1}{56}-\frac{1}{61}+\frac{1}{61}-\frac{1}{66}\right)\)
\(=\frac{1}{5}\times\left(\frac{1}{11}-\frac{1}{66}\right)\)
\(=\frac{1}{5}\times\frac{5}{66}=\frac{1}{66}\)
\(\frac{\left(16-8:5\right)x177}{199x2001}\frac{\left(16-16\right)x177}{199x2001}=\frac{0x177}{199x2001}=\frac{0}{199x2001}=0\)