Answer
$0.65\times84+0.15\times80+0.2w \geq 85$
$0.65\times80+0.15\times100+0.2x \geq 85$
$0.65\times 75+0.15\times95+0.2y \geq 85$
$0.65\times80+0.15\times90+0.2z \geq 85$
Work Step by Step
Write inequalities
For Amy: $0.65\times84+0.15\times80+0.2w \geq 85$
For Brian: $0.65\times80+0.15\times100+0.2x \geq 85$
For Clara: $0.65\times 75+0.15\times95+0.2y \geq 85$
For Dan: $0.65\times80+0.15\times90+0.2z \geq 85$