Rút gọn phân số

17.

a) - 12

b) - 15

c) -20

d) -12; -12; 30

15. a) \(\frac{-6}{-9}\)

b) \(\frac{12}{-21}\)

c) \(\frac{9}{-2}=\frac{9.\left(-4\right)}{\left(-2\right).\left(-4\right)}=\frac{-36}{8}\)

d) \(\frac{11}{-2}=\frac{11.\left(-4\right)}{\left(-2\right).\left(-4\right)}=\frac{-44}{8}\)

16.

a) \(\frac{-5}{2}\)

b) -2

c) \(\left(-7\right)\ ;\ \frac{2}{3}\)

d) \(\left(-3\right);\ \frac{-6}{-5}\)