min = p 1(d 1 plus+d 1 MINUS)+p2 * D2 plus+P3 *(2d 3 1 MINUS+d 32 MINUS)+P4(3d 3 1 plus+2d 32 plus)

(25t 1+ 10t 2)+d 1 plus-d 1 MINUS = 27500

900+D2 plus -D2 minus+100=t 1

900+d 3 1 plus-d 3 1 MINUS = t 1

320+d32plus-d32minus=t2

How to solve the linear programming problem that needs to be solved by layers will be discussed in the evening.