A、B的平均数是170,A+B=170×2=340,
B,C,D的平均数是100.B+C+D = 100×3 = 300
加起来是:A+B+C+D+B = 340+300=640
A+B+C+D =120×4=480
B= 640-480 = 160
列综合算式为:
170×2+100×3-120×4 = 160
A、B的平均数是170,A+B=170×2=340,
B,C,D的平均数是100.B+C+D = 100×3 = 300
加起来是:A+B+C+D+B = 340+300=640
A+B+C+D =120×4=480
B= 640-480 = 160
列综合算式为:
170×2+100×3-120×4 = 160