正方形的边长扩大2倍,面积也扩大2倍。 。(判断对错)
98-49=59
()
(80-9.8)×-1.32 =70.2×-1.32 =28.08-1.32 =26.76()
18.1+(3-0.299÷0.23)×1 =18.1+1.6×1 =18.1+1.6 =19.7()
(1÷1-1)÷5.1 =(1-1)÷5.1 =0÷5.1 =0()