Question

[Lê Minh Hoàng]

12/5-3/7          27-3/8             19/15+4/5           2/13+6/11         7+9/10              27/4 - 3

Answer 1

[phạm quang lộc]

\(\frac{12}{5}\)-\(\frac{3}{7}\)=\(\frac{12x7}{5x7}\)-\(\frac{3x5}{7x5}\)=\(\frac{84}{35}\)-\(\frac{15}{35}\)=\(\frac{84-15}{35}\)=\(\frac{69}{35}\)

27 - \(\frac{3}{8}\)=\(\frac{213}{8}\)

\(\frac{19}{15}\)+\(\frac{4}{5}\)=\(\frac{19x5}{15x5}\)+\(\frac{4x15}{5x15}\)=\(\frac{95}{75}\)+\(\frac{60}{75}\)=\(\frac{95+60}{75}\)=\(\frac{155}{75}\)

\(\frac{2}{13}\)+\(\frac{6}{11}\)=\(\frac{2x11}{13x11}\)+\(\frac{6x13}{11x13}\)=\(\frac{22}{143}\)+\(\frac{78}{143}\)=\(\frac{22+78}{143}\)=\(\frac{100}{143}\)

7 + \(\frac{9}{10}\)=\(\frac{79}{10}\)

\(\frac{27}{4}\)- 3 = \(\frac{77}{3}\)