问题
填空题
若2x-3=1,y2-y=2,则3y2+2x2y-9y-(2y-x)的值为______.
答案
∵2x-3=1,
∴x=2,
∵3y2+2x2y-9y-(2y-x)=3y2+8y-9y-(2y-2)
=3y2+8y-9y-2y+2
=3y2-3y+2
=3(y2-y)+2
=3×2+2
=8.
故答案为8.
若2x-3=1,y2-y=2,则3y2+2x2y-9y-(2y-x)的值为______.
∵2x-3=1,
∴x=2,
∵3y2+2x2y-9y-(2y-x)=3y2+8y-9y-(2y-2)
=3y2+8y-9y-2y+2
=3y2-3y+2
=3(y2-y)+2
=3×2+2
=8.
故答案为8.