a) A = 3/7
b) B = 73/13
c) C = 37/7
d) D = 12
ba câu a) ,b) ,c) bn đổi ra hỗn số giúp mk nha
tick cho tớ nha
a) \(A=11\dfrac{3}{13}-\left(3\dfrac{4}{7}-6\dfrac{3}{13}\right)\)
\(=11\dfrac{3}{13}-3\dfrac{4}{7}-6\dfrac{3}{13}\)
\(=\left(11\dfrac{3}{13}-6\dfrac{3}{13}\right)-3\dfrac{4}{7}\)
\(=1\dfrac{3}{7}\)
b) \(B=\left(7\dfrac{4}{9}+3\dfrac{8}{13}\right)-5\dfrac{4}{9}\)
\(=7\dfrac{4}{9}+3\dfrac{8}{13}-5\dfrac{4}{9}\)
\(=\left(7\dfrac{4}{9}-5\dfrac{4}{9}\right)+3\dfrac{8}{13}\)
\(=2+3\dfrac{8}{13}\)
\(=5\dfrac{8}{13}\)
c) \(C=\dfrac{-2}{7}.\dfrac{5}{11}+\dfrac{-2}{7}.\dfrac{6}{11}+5\dfrac{4}{7}\)
\(=\dfrac{-2}{7}.\left(\dfrac{5}{11}+\dfrac{6}{11}\right)+5\dfrac{4}{7}\)
\(=\dfrac{-2}{7}+5\dfrac{4}{7}\)
\(=\dfrac{-5}{7}+\dfrac{12}{7}\)
\(=\dfrac{7}{7}=1\)
d) \(D=0,7.1\dfrac{3}{5}.30.0,375.\dfrac{4}{7}\)
\(=\dfrac{7}{10}.\dfrac{8}{5}.30.\dfrac{375}{1000}.\dfrac{4}{7}\)
\(=\dfrac{36}{5}\)
\(=7,2\)