A:136
B:64
C:50
D:81
Lucy is eight-year-old girl with long black hair.
运用等式性质进行的变形,正确的是( )
67 ÷7=____ 19×3 =____ 1+50%=____ 45×15 =____
34×15 ÷ 34×15 =____ 16 + 56 × 15 =____ 12 ×101- 12 =____ 34 ×9× 43 =____
已知 a≥0,b≥0 ,且a+b=2 ,则( )