Question

tính nhanh : 

B= 19.25 + 9.95 + 19.30

Answer 1

B=19.25+9.95+19.30

  =19.25+9.5.19+19.30

  =19.25+45.19+19.30

  =19(25+45+30)

  =19.100

  =1900

Answer 2

B = 19.25 + 9.95 + 19.30

B = 19 . 25 + 45 . 19 + 19 . 30

B = 19 . ( 25 + 45 + 30 )

B = 19 . 100

B = 1900

Answer 3

B = 19 x 25 + 9 x 95 + 19 x 30

B = 19 x 25 + 9 x 5 x 19 + 19 x 30

B = 19 x ( 25 + 9 x 5 + 30 )

B = 19 x 100 = 1900