Question

已知|x+y+2|+（2x-3y-1）²=0 求 1.x、y的值 2.2x³-x²-3y³的值

Answer 1

1.

|x+y+2|+（2x-3y-1）²=0

所以

|x+y+2|=0,（2x-3y-1）²=0

x+y=-2

2x-3y=1

解得

x=-1

y=-1

所以

2.

2x³-x²-3y³

=-2-1+3

=0