Tìm y hoặc tính giá trị của biểu thức
a) y - 3 = 5 : 10 b) 1 x ( 2 + 3 ) : 14
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4 12 3 3 5 10 9
\(a,y-\dfrac{3}{4}=\dfrac{5}{12}:\dfrac{10}{3}\\ \Rightarrow a,y-\dfrac{3}{4}=\dfrac{5}{12}.\dfrac{3}{10}\\ \Rightarrow y-\dfrac{3}{4}=\dfrac{1}{8}\\ \Rightarrow y=\dfrac{1}{8}+\dfrac{3}{4}\\ \Rightarrow y=\dfrac{7}{8}\\ b,\dfrac{1}{3}\times\left(\dfrac{2}{5}+\dfrac{3}{10}\right):\dfrac{14}{9}=\dfrac{1}{3}\times\left(\dfrac{4}{10}+\dfrac{3}{10}\right):\dfrac{14}{9}=\dfrac{1}{3}\times\dfrac{7}{10}\times\dfrac{9}{14}=\dfrac{3}{20}\)