计算。4-2= 4-3= 5-3= 2-0= 1-0=3-1= 5-2= 3-2= 4-1= 1-0=2-2= 0-0= 3-2= 3-1= 2-1=5-4= 5-5= 4-3= 3-2= 5-5=
(×+)÷÷[(+)×]
(+)×15×11 37.5+19.5÷(2.5×4)
12×103-4500÷75×[÷(×)]
×+÷