x^2+(6-y)^2=(8-x)^2+y^2
4x-3y-7=0
8-x<6
x<6
所以6>x>2
2. S=(x+8-x)*6/2-x*(6-y)/2-y*(8-x)/2
=xy-3x-4y+24
= (4x^2-32x+100)/3
3. 最小为12,最大为52/3
x^2+(6-y)^2=(8-x)^2+y^2
4x-3y-7=0
8-x<6
x<6
所以6>x>2
2. S=(x+8-x)*6/2-x*(6-y)/2-y*(8-x)/2
=xy-3x-4y+24
= (4x^2-32x+100)/3
3. 最小为12,最大为52/3