m﹣2+xm﹣1y+(3﹣m)xm﹣2y﹣nx2ym﹣3+xm﹣4y2 .
(1)已知x=﹣2,y=﹣1,求5xy2﹣{2x2y﹣[3xy2﹣﹙4xy2﹣2x2y)]}的值,
(2)关于x,y的多项式6mx2+4nxy+2x+2xy﹣x2+y+4不含二次项,求6m﹣2n+2的值.