a, 1/3:7/6-15/7
=1/3.6/7 -15/7
=1.2/7 -15/7
= 2/7-15/7
=-13/7
b,16/3- (11/5 +13/3)
=16/3-11/5-13/3
=(16/3-13/3)-11/5
=1-11/5
=-6/5
c,-5/11-4/13+(-5)/11.9/11+ 38/11
=-5/11.(4/13+9/13) -38/11
=-5/11.1-38/11
=-43/11
d,2/7.75/100 +(25/100 +11/20): 7/3
=2/7.75/100+ 25/100 -11/20:7/3
=2/7.(75/100 +25/100)-11/20:7/3
=2/7 .1-11/20:7/3
=2/7-11/20:7/3
=1/20
NẾU ĐC BN CHO MIK CTLHN NHA CẢM ƠN !