Question

mấy bn giúp mình nhé:

1) tính thuận tiện:

a) 45.32+45.66+45+45

b) (2013+2014+2015)x(30.12-18.20)

c) (12+12+12.88)x45+12.10

Answer 1

a)45x32+45x66+45+45

=45x(32+66+1+1)

=45x100

=4500

Answer 2

a.45.32+45.66+45.2

= 45.(32+66+2)

=45.100=4500

b.(2013+2014+2015).(20+10).12-18.20

=(2013+2014+2015).(30.12-(12+6).20)

=(2013+2014+2015).(30*12-12.20-6.20)

=(2013+2014+2015).(12.(30-20)-6.20)

=(2013+2014+2015).(12.10-6.20)

=(2013+2014+2015).(120-120)

=(2013+2014+2015).0

=0

c.(12+12+12.88).45+12.12

=(12.(1+1+88)).45+12.10

=12.90.45+120

=12.9.10.5.9+120

=1080.5.9+120

=5400.9+120

=48600+120

=48720

nho k cho to nhe