解:3.2+()=4.5-()2()=4.5-3.2=1.3()=0.653.2+(0.65)=4.5-(0.65)=3.85
3.2加1.3等于4.5减3.2
3.2+1.3=4.5-1.3
3.2+@=4.5-X=@+x=4.5-3.2=@+x=1.3