Đáp án:
Giải thích các bước giải:
bài 11:
a. −2/7.2/18=(−2).2/17.8=−42/56=−3/4
b. 0,24.−15/4=24/100.−15/4=24.(−15)/100.4=−9/10
c. (−2).(−7/12)=(−2).(−7)/12=14/12=7/6
d. (−3/25):6=(−3/25).1/6=(−3).1/25.6=−1/50
bài 12:
a. −5/16=5.(−1/16)
b. −5/16=−1/2:8/5
bài 13:
a. −3/4.12/−5.(−25/6)=(−3).12.(−25)/4.(−5).6=−15/2
b. (−2).−38/21.−7/4.(−3/8)=(−2).(−38).(−7).(−3)/21.4.8=19/8
c. (11/12:33/16).3/5=(11/12.16/33).3/5=4/15.3/5=12/75
d. 7/23.[(−8/6)−45/18]=7/23.[(−24/18)−45/18]=7/23.−23/6=−7/6
