Question

Tính hợp lí:

A = \(\left(\frac{-4}{5}+\frac{4}{3}\right)+\left(\frac{-5}{4}+\frac{14}{5}\right)-\frac{7}{3}\)

B= \(\frac{8}{3}.\frac{2}{5}.\frac{3}{8}.10.\frac{19}{92}\)

C= \(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{14}+1\frac{5}{7}\)

Answer 1

A= (-4/5+4/3)+(-5/4+14/5)-7/3

= 8/15+31/20-7/3

= 25/12-7/3

= -1/4

B= 8/3.2/5.3/8.10.19/92

= 16/15.3/8.10.19/92

= 2/5.10.19/92

= 4.19/92

= 19/23

C= \(\frac{-5}{7}\).\(\frac{2}{11}\)+\(\frac{-5}{7}\).\(\frac{9}{14}\)+1\(\frac{5}{7}\)

=\(\frac{-5}{7}\).\(\frac{2}{11}\)+\(\frac{-5}{7}\).\(\frac{9}{14}\)+\(\frac{12}{7}\)

= \(\frac{-10}{77}\)+\(\frac{-5}{7}\).\(\frac{9}{14}\)+\(\frac{12}{7}\)

= \(\frac{-10}{77}\)+\(\frac{-45}{98}\)+\(\frac{12}{7}\)

= \(\frac{-635}{1078}\)+\(\frac{12}{7}\)

= \(\frac{1213}{1078}\)

Answer 2

thanks nhìu