已知:x+y=6,xy=-3,则 xyy+yxx=

问题描述:

已知:x+y=6,xy=-3,则 xyy+yxx=

xyy+yxx=xy(x+y)=3*6=18

xyy+yxx=xy*(x+y)=-3*6=-18

将xy提取公因式变成:
xy(x+y)=-3*6=-18

xyy+yxx=xy(x+y)=-3*6=-18