y-{y-2x+［5x-3(y+2x)+6y］},其中x= - 1/3,y= 1/8.
问题描述：
y-{y-2x+［5x-3(y+2x)+6y］},其中x= - 1/3,y= 1/8.
答
y-{y-2x+［5x-3(y+2x)+6y］}
=y-[y-2x+(5x-3y-6x+6y)]
=y-[y-2x-x+3y]
=y-4y+3x
=3x-3y
=3×(-1/3)-3×1/8
=-11/8