Question

A=8x平方y-6xy的平方-3xy,B=7xy平方-2xy 5x平方y,若A-1/2B+ c =O,其中x=3/2,y=-0.

A=8x平方y-6xy的平方-3xy,B=7xy平方-2xy 5x平方y,若A-1/2B+ c =O,其中x=3/2,y=-0.5

Answer 1

A-1/2B+ c =O
C=B/2-A
=1/2(7xy平方-2xy +5x平方y)-(8x平方y-6xy的平方-3xy)
=7xy²/2-xy+5x² y/2-8x²y+6xy²+3xy
=19xy²/2+2xy-11x²y/2

Answer 2

解：由题意得：
½B=3.5xy²－1xy－2.5x²y
A－½B=8x²y－6xy²－3.5xy²－1xy－2.5x²y
=5.5x²y－9.5xy²－xy
c=﹣5.5x²y＋9.5xy²＋xy
答：c=9.5xy²＋xy﹣5.5x²y