设(y-3)/(x-5)=k,即：y=kx-5k+3代人椭圆方程得：9x^2+16(kx-5k+3)^2=144整理得：(9+16k^2)x^2+32(-5k+3)kx+(-5k+3)^2-144=0根据题意得：△>=0即：[32(-5k+3)k]^2-4(9+16k^2)[(-5k+3)^2-144]>=0解得：0...