采用面积法:
S△PBC=S四边形EHGF-S△BEP-S△BHC-S△CKP=(x+2)(y+1)-1/2y(x+2)-1/2*2*1-1/2x(y+1)=y+x/2+1
S△PAD=S四边形JODF-S△PAJ-S△PFD-S△OAD=4y-1/2x(y-3)-1/2*3*4-1/2y(4-x)=3/2y+3/2x-6+1/2xy
因为:S△PBC=S△PAD
所以:y+x/2+1=3/2y+3/2x-6+1/2xy
推出:1/2y+x-7+1/2xy=0
y=(14-2x)/(1+x)
0≤x≤7