1.(2X+Y)的2次方-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)2.(X+2Y)的2次方-2(X-Y)(X+Y)+2Y(X-3Y)

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1.(2X+Y)的2次方-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)2.(X+2Y)的2次方-2(X-Y)(X+Y)+2Y(X-3Y)

1.(2X+Y)的2次方-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)2.(X+2Y)的2次方-2(X-Y)(X+Y)+2Y(X-3Y)
1.(2X+Y)的2次方-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)
2.(X+2Y)的2次方-2(X-Y)(X+Y)+2Y(X-3Y)

1.(2X+Y)的2次方-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)2.(X+2Y)的2次方-2(X-Y)(X+Y)+2Y(X-3Y)
1.(2X+Y)^2-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)
解原式=4X^2+Y^2+4XY-2X^2-2XY+XY+Y^2-2(X^2-4Y^2)
=4X^2+Y^2+4XY-2X^2-2XY+XY+Y^2-2X^2+8Y^2
=4X^2-2X^2-2X^2+Y^2+Y^2+8Y^2+4XY-2XY+XY
=10Y^2+3XY
2.(X+2Y)^2-2(X-Y)(X+Y)+2Y(X-3Y)
解原式=X^2+4Y^2+4XY-2(X^2-Y^2)+2XY-6Y^2
=X^2+4Y^2+4XY-2X^2+2Y^2+2XY-6Y^2
=X^2-2X^2+4Y^2+2Y^2-6Y^2+4XY+2XY
=-X^2+6XY