Question

1 4(X^2+Y)(X^2-Y)-(2X^2-Y)^,其中X=-1/6,Y=9

Answer 1

1.4(X^2+Y)(X^2-Y)-(2X^2-Y)^ 最后的指数没有标出

2.|X-2a|+(y+3)^2=0说明|X-2a|=0,(y+3)^2=0得X=2a,y=-3

由已知可得B-2A=-x-5y=a,将X=2a,y=-3带入得x=10,y=-3

带入A=2X^2-3XY+Y^2-X+2Y=283

3.化简（2X＾2＋XY＋3Y＾2）－（X＾2－XY＋2Y＾2）=X^2+2xy+y^2=36