Question

1/ Thực hiện phép tính

a.(3/8+-3/4+7/12) . 5/6+1/2b.1/2+3/4-(3/4+1/2)

c.\(^{ }_{\dfrac{6}{\dfrac{5}{12}}}\):\(^{ }_{\dfrac{2}{\dfrac{3}{4}}}\)+\(^{ }_{\dfrac{11}{\dfrac{1}{4}}}\).(1/3-1/5)

giúp mk vs mk đang gấp

Answer 1

a)

\(\left[\dfrac{3}{8}+\left(-\dfrac{3}{4}+\dfrac{7}{12}\right)\right].\dfrac{5}{6}+\dfrac{1}{2}\)

\(=\dfrac{5}{24}.\dfrac{5}{6}+\dfrac{1}{2}\)

\(=\dfrac{25}{144}+\dfrac{1}{2}\)

\(=\dfrac{97}{144}\)

b)

\(\dfrac{1}{2}+\dfrac{3}{4}-\left(\dfrac{3}{4}+\dfrac{1}{2}\right)\)

\(=\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{3}{4}-\dfrac{1}{2}\)

\(=0\)

c)

\(\dfrac{6}{\dfrac{5}{12}}:\dfrac{2}{\dfrac{3}{4}}+\dfrac{11}{\dfrac{1}{4}}\left(\dfrac{1}{3}-\dfrac{1}{5}\right)\)

\(=\dfrac{27}{5}+\dfrac{11}{\dfrac{1}{4}}.\dfrac{2}{15}\)

\(=\dfrac{27}{5}+\dfrac{88}{15}\)

\(=\dfrac{169}{15}\)