Answer:
[tex]4x+6y+8z\le 210\\ \\2x+4y+2z\le 150\\ \\2x+2y+4z\le 90\\ \\x\ge 0\\ \\y\ge 0\\ \\z\ge 0[/tex]
Step-by-step explanation:
Let
Cleaning requires 4 minutes for type A, 6 minutes for type B and 8 minutes for type C. In total, 3.5 hours, then
[tex]4x+6y+8z\le 3.5\cdot 60[/tex]
Cutting requires 2 minutes for type A, 4 minutes for type B and 2 minutes for type C. In total, 2.5 hours, then
[tex]2x+4y+2z\le 2.5\cdot 60[/tex]
Packaging requires 2 minutes for type A, 2 minutes for type B and 4 minutes for type C. In total, 1.5 hours, then
[tex]2x+2y+4z\le 1.5\cdot 60[/tex]
Note that
[tex]x\ge 0\\y\ge 0\\z\ge 0[/tex]
Hence, we have 6 inequalities:
[tex]4x+6y+8z\le 210\\ \\2x+4y+2z\le 150\\ \\2x+2y+4z\le 90\\ \\x\ge 0\\ \\y\ge 0\\ \\z\ge 0[/tex]