3×[(3x-2y)+(x-3y+1)]-2×[2×(3x-2y)-(x-3y+1)]等于几
问题描述:
3×[(3x-2y)+(x-3y+1)]-2×[2×(3x-2y)-(x-3y+1)]等于几
答
解3×[(3x-2y)+(x-3y+1)]-2×[2×(3x-2y)-(x-3y+1)]
=[3(3x-2y)+3(x-3y+1)]-[4(3x-2y)-2(x-3y+1)]
=3(3x-2y)+3(x-3y+1)-4(3x-2y)+2(x-3y+1)
=3(3x-2y)-4(3x-2y)+3(x-3y+1)+2(x-3y+1)
=-(3x-2y)+5(x-3y+1)
=-3x+2y+5x-15y+5
=3x-13y+5.
答
原式=3(3x-2y+x-3y+1)+2(6x-4y-x+3y-1)
=3(4x-5y+1)+2(5x-y-1)
=12x-15y+3+10x-2y-2
=22x-17y+1