另一加数为:49.31-26.8=49.31-(27-0.2)=49.31-27+0.2=22.31+0.2=22.51正确结果为:22.51+29.3=22.51+(30-0.7)=22.51+30-0.7=52.51-0.7=51.81谢谢,请采纳
49.31-26.8=22.5122.51+29.3=51.81