[简答题]

5(a²b—ab²）—（ab²+3a²b） 其中a=二分之一  b=负一                
小王种植了大豆玉米和芋头共200m² 其中大豆的面积是（x-2）m²  玉米的种植面积是大豆的两倍 求芋头的种植面积
已知A=X³+2y³—xy²，B=-Y+x³+2xy²，其中x=三分之一 y=2 求A-B的值

A——Employee relations
B——Basic salary
C——Night shift
D——Attendance book
E——Human resources management
F——Work permit
G——Employment injury insurance
H——Housing fund
I——Annual salary
J——Year-end bonus
K——Contract of service
L——Evaluation of employees
M——Sick leave
N——Coffee break
O——Unemployment insurance
P——Minimum wage
Q——Quality management

A——Business Management B——Marketing Management
C——International Business Law D——Management Information Systems
E——Financial Management
F——The World Environment and International Business
G——Managerial Economics and Decision Models
H——Operations Management
I——Human Resource Management J——Managerial Accounting
K——Economic Law L——Currency Banking Science
M——Practical International Trade N——Equipment Management
O——Western Economics P——Management and Labor

A——traffic regulation B——mark car stop
C——traffic post D——single line
E——carriage-way F——speed limit
G——no through traffic H——passing bay
I——restricted waiting J——caution animals
K——silent zone L——driving without license
M——slight impact N——hit-run driver
O——traffic jam P——public car only