Tính nhanh a) 13/23 . 7/11 + 10/23 . 7/11 b) 5/9 . 23/11 - 1/11 . 5/9 + 5/9

a) 1323.711+1023.711

=711.1323+1023

=711.2323=711

b) 59.2311−111.59+59

=59.2311−111+1

=59.2211+1=59.3=53

c) −49+35:1317+25−59:1317

=−49+35.1713+25−59.1713

=1713.−49+35+25−59

=1713.−49−59+35+25=1713.−1+1=0.

d) 316:322−311+316:110−25

=316:322−622+316:110−410

=316:−322+316:−310

=316.22−3+316.10−3

=316.22−3+10−3=316.32−3=−2