thực hiện phép tính
a/ \(\frac{15}{34}\)+ \(\frac{7}{21}\)+ \(\frac{19}{34}\)- 1\(\frac{15}{17}\)+ \(\frac{2}{3}\)
b/ 16\(\frac{2}{7}\): (\(\frac{-3}{5}\)) - 28\(\frac{2}{7}\): (\(\frac{-3}{5}\))
c/ ( -2 ) 3 . (\(\frac{3}{4}\)- 0,25 ) : ( 2\(\frac{1}{4}\)- 1\(\frac{1}{6}\))
GIÚP MK NHÉ , ARIGATO , CÁM ƠN RẤT NHIỀU
a/ \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{32}{17}+\frac{14}{21}=\left(\frac{15}{34}+\frac{19}{34}\right)+\left(\frac{7}{21}+\frac{14}{21}\right)-\frac{32}{17}=1+1-\frac{32}{17}=\frac{2}{17}\)
a) \(\frac{15}{34}\)+ \(\frac{7}{21}\)+ \(\frac{19}{34}\)- \(1\frac{15}{17}\)+ \(\frac{2}{3}\)
= ( \(\frac{15}{34}\)+ \(\frac{19}{34}\)) + ( \(\frac{7}{21}\)+ \(\frac{2}{3}\)) - \(\frac{32}{17}\)
= \(\frac{34}{34}\)+ ( \(\frac{7}{21}\)+ \(\frac{14}{21}\)) - \(\frac{32}{17}\)
= 1 + \(\frac{21}{21}\)- \(\frac{32}{17}\)
= 1+1-\(\frac{32}{17}\)
= 2-\(\frac{32}{17}\)
= \(\frac{34}{17}\)-\(\frac{32}{17}\)
= \(\frac{2}{17}\)
b) \(16\frac{2}{7}\): (\(\frac{-3}{5}\))- \(28\frac{2}{7}\): (\(\frac{-3}{5}\))
= (\(16\frac{2}{7}\)- \(28\frac{2}{7}\)) : \(\frac{-3}{5}\)
= -12 . \(\frac{-5}{3}\)
= \(\frac{-12.\left(-5\right)}{3}\)
= \(\frac{-4.\left(-5\right)}{1}\)
= 20
c) \(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)
= \(-8.\left(\frac{3}{4}-\frac{1}{4}\right):\left(\frac{9}{4}-\frac{7}{6}\right)\)
=\(-8.\frac{2}{4}:\left(\frac{27}{12}-\frac{14}{12}\right)\)
=\(-4:\frac{13}{12}\)
=\(-4.\frac{12}{13}\)
= \(\frac{-48}{13}\)