先化简 再求值:求4x2y-[6xy-3(4xy-2)-x2y]+1的值,其中x=2,y=1⼀2

2025-05-19 15:46:09
推荐回答(5个)
回答(1):

4x2y-[6xy-3(4xy-2)-x2y]+1
=4x²y-6xy+12xy-6+x²y+1
=5x²y+6xy+1
=5x2²x1/2+6x2x1/2+1
=10+6+1
=17 是这样把!!!!!!!!!!!

回答(2):

我先告诉你哈,这个公式呢 4x2y=8xy 那这道题就很简单了吧

回答(3):

4x2y-[6xy-3(4xy-2)-x2y]+1
=4x²y-6xy+12xy-6+x²y+1
=5x²y+6xy+1
=5x2²x1/2+6x2x1/2+1
=10+6+1
=17

回答(4):

=4x2y-6xy+3(4xy-2)+x2y+1 =8xy-6xy+12xy-6+2xy+1 =16xy-5 =16*2*1/2-5 =11

回答(5):

4x2y-[6xy-3(4xy-2)-x2y]+1

=4x2y-6xy+3(4xy-2)+x2y+1
=5x2y+6xy-5
=5*4*1/2+6*2*1/2-5
=10+6-5
=11