a+3=0.2,
a= 0.2-0.3 = -0.1
b-1又二分之一=0.8,
b= 0.8 + 1.5 =2.3
c-0.5=0.6
c= 0.5+0.6 = 1.1
则a-b+c= -0.1 -2.3 +1.1 = -1.3
有什么不明白可以对该题继续追问
请及时选为满意答案,