巧算:2.2*0.4*1.25*2.6 1.625+2.625+3.625+…+80.625 5.5*6.6+6.6*7.7+7.7*8.8+8.8*9.9

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/02 08:48:46
巧算:2.2*0.4*1.25*2.6 1.625+2.625+3.625+…+80.625 5.5*6.6+6.6*7.7+7.7*8.8+8.8*9.9

巧算:2.2*0.4*1.25*2.6 1.625+2.625+3.625+…+80.625 5.5*6.6+6.6*7.7+7.7*8.8+8.8*9.9
巧算:2.2*0.4*1.25*2.6 1.625+2.625+3.625+…+80.625 5.5*6.6+6.6*7.7+7.7*8.8+8.8*9.9

巧算:2.2*0.4*1.25*2.6 1.625+2.625+3.625+…+80.625 5.5*6.6+6.6*7.7+7.7*8.8+8.8*9.9
2.2*0.4*1.25*2.6=1.1*0.8*1.25*2.6=1.1*2.6=2.86
1.625+2.625+3.625+…+80.625 =1+2+……+80+0.625*80
5.5*6.6+6.6*7.7+7.7*8.8+8.8*9.9=1.21*(5*6+6*7+7*8+8*9)