4x+3y≤ 1 10，

When x=27, y=0 and x+y=27.

When x=26, y=2 and x+y=28.

When x=25, y=3 and x+y=28,

When x=24, y=4 and x+y=28,

When x=23, y=6 and x+y=29,

. . . .