Question

已知X+Y=—4,怎么样求1/2(X+Y)---4(X-Y)+3(X-Y)--2/3(X+Y)+(X--Y)的值

Answer 1

1/2(X+Y)-4(X-Y)+3（X-Y）-3/2(X+Y)+(X-Y)
=1/2(X+Y)-3/2(X+Y)+3（X-Y）+(X-Y)-4(X-Y)
=-(X+Y)
=-(-4)
=4

Answer 2

1/2(X+Y)---4(X-Y)+3(X-Y)--2/3(X+Y)+(X--Y)
=[1/2(X+Y)-2/3(X+Y)]+[-4(X-Y)+3(X-Y)+(X--Y)]
=-1／6(X+Y)
=﹣1／6×(-4)
=2／3

Answer 3

1/2(X+Y)---4(X-Y)+3(X-Y)--2/3(X+Y)+(X--Y)
=[1/2(X+Y)-2/3(X+Y)]+[-4(X-Y)+3(X-Y)+(X--Y)]
=-1／6(X+Y)
=﹣1／6×(-4)
=2／3

Answer 4

=-1／6(X+Y)
=﹣1／6×(-4)
=2／3

Answer 5

最后等于-x-y=4