2 - 5/7 + 9/21 = 12/7
5/8 : 3 x 24/25 = 1/5
k minh di
2 - \(\frac{5}{7}\)+\(\frac{9}{21}\)= \(\frac{9}{7}\)+\(\frac{9}{21}\)= \(\frac{12}{7}\)
\(\frac{5}{8}\): 3 x\(\frac{24}{25}\)= \(\frac{5}{24}\)x \(\frac{24}{25}\)= \(\frac{1}{5}\)
mk nhanh nhất tk mk nha