2xy-{5x-3[xy-1/3x(y+1)]-4xy} 去掉括号,并合并.
问题描述:
2xy-{5x-3[xy-1/3x(y+1)]-4xy} 去掉括号,并合并.
答
2xy-{5x-3[xy-1/3x(y+1)]-4xy}
=2 xy - {5 x+ x + 3 xy + x y - 4 xy}
=-6 x + 3 xy - x y