Question

tính nhanh 

B =136 .68+34.272

Answer 1

B=35.12+65.13

  =35.12+65.12+65

  =(35+65).12+65

  =100.12+65

  =1200+65=1265

Answer 2

35.12 +65.13

=35.12 +65.12 +65

=12. ( 65+35) +65

=12.100 +65

=1200+65=1265

Answer 3

B)=35X12+65X12+65

B=12(65+35)+65

B=12X100+65

B=1200+65=1265