一次函数y=kx+b的图像经过点A(0,-6),B(6,3),与x轴交于点C

将A(0,-6),B(6,3)坐标代入y=kx+b得-6=b,3=6k+b,解得k=3/2则函数方程为y=3x/2-6,当y=0时,x=4,即点C坐标为(4,0)S△PAC=PC*6/2=3PC,△PCB=PC*3/2=(3/2)PCS△PAB=S△PAC+S△PCB=3PC+(3/2)PC=(9/2)PC设P点坐标为(m,0)当m4时：则PC=m-4,S△PAB=(9/2)(m-4)=(9/2)m-18=18,m=8所以点P坐标为(0,0)或(8,0)