先化简,再求值。求4x^2y-{6xy-3(4xy-2)-x^2y}+1,其中X=2,y=-1⼀2

2025-05-17 05:32:51
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回答(1):

4x^2y-{6xy-3(4xy-2)-x^2y}+1
=4x²y-6xy+12xy-6+x²y+1
=5x²y+6xy-5
=5*4*(-1/2)+6*2*(-1/2)-5
=-21