简便计算 (18 19:5:39)(1+0.12+0.23)X(0.12+0.23+0.34)-(1+0.12+0.23+0.34)X(0.12+0.23)如果A▲B=3A-2B ,求2▲( 3▲4     )

问题描述:

简便计算 (18 19:5:39)
(1+0.12+0.23)X(0.12+0.23+0.34)-(1+0.12+0.23+0.34)X(0.12+0.23)
如果A▲B=3A-2B ,求2▲( 3▲4     )

第二题好算
3*2-2*(3*3-2*4)=4

1.原式=1*(0.12+0.23+0.34)+(0.12+0.23+0.34)*(0.12+0.23)-[1*(0.12+0.23)+(0.12+0.23)*(0.12+0.23+0.34)]= (0.12+0.23+0.34)+(0.12+0.23+0.34)*(0.12+0.23)-(0.12+0.23)-(0.12+0.23)*(0.12+0.23+0.34)=...