a)66.36+66.65-63
=66.(36+65-1)
=66.100
=6600
b)57.36+57.63+60
=57.(36+57)+60
=57.93+60
=5301+60
=5361
c)35.(48+50)+72
=35.98+72
=3430+72
=3502
d)15.66+30.17
=15.66+15.2.17
=15.66+15.34
=15.(66+34)
=15.100
=1500
e)45.56+15.32
=15.3.56+15.32
=15.168+15.32
=15.(168+32)
=15.200
=3000
nhớ **** cho mình nha