Nội dung bài giảng
Tính bằng hai cách:
a) \(\frac{7}{11}\) : \(\frac{3}{5}\) + \(\frac{4}{11}\) : \(\frac{3}{5}\) ;
b) (6,24 + 1,26) : 0,75 ;
Bài giải:
a) Cách 1: \(\frac{7}{11}\) : \(\frac{3}{5}\) + \(\frac{4}{11}\) : \(\frac{3}{5}\) = \(\frac{7}{11}\) x \(\frac{5}{3}\) + \(\frac{4}{11}\) x \(\frac{5}{3}\) = \(\frac{35}{33}\) + \(\frac{20}{33}\) = \(\frac{55}{33}\) = \(\frac{5}{3}\)
Cách 2: \(\frac{7}{11}\) : \(\frac{3}{5}\) + \(\frac{4}{11}\) : \(\frac{3}{5}\) = (\(\frac{7}{11}\) + \(\frac{4}{11}\) ) : \(\frac{3}{5}\) = \(\frac{11}{11}\) : \(\frac{3}{5}\) = 1 : \(\frac{3}{5}\) = \(\frac{5}{3}\)
b) Cách 1 : (6,24 + 1,26) : 0,75 = 7,5 : 0,75 = 10
Cách 2: 6,24 + 0,75 : 1,26 : 0,75 = 8,32 + 1,68 = 10.