5\nselect the correct location on the coordinate plane.\nruhana owns a workshop where her team of…

5\nselect the correct location on the coordinate plane.\nruhana owns a workshop where her team of technicians refurbishes tv sets and dvd players, and then she sells them for a profit. she has a weekly sales target of at least 35 tv sets or dvd players. additionally, she must ensure that her team collectively works at least 100 hours each week. it takes 4 hours to refurbish a tv set and 2 hours to refurbish a dvd player.\nit costs $75 to refurbish a tv set and $40 to refurbish a dvd player. if ruhana wants to minimize costs, which point represents the optimal number of tv sets and dvd players that her team should refurbish each week?
Answer
Explanation:
Step1: Define variables
Let $x$ be the number of TV - sets and $y$ be the number of DVD - players.
Step2: Set up constraints
- Sales target constraint: $x + y\geq35$.
- Working - hours constraint: $4x + 2y\geq100$, which simplifies to $2x + y\geq50$. Also, $x\geq0,y\geq0$ since the number of items cannot be negative.
Step3: Define the cost function
The cost function $C=75x + 40y$.
Step4: Rewrite constraints in slope - intercept form
The first constraint $y\geq - x + 35$. The second constraint $y\geq - 2x+50$.
Step5: Find the intersection points of the boundary lines
Intersection of $y=-x + 35$ and $y=-2x + 50$: Set $-x + 35=-2x + 50$. Add $2x$ to both sides: $2x - x+35=50$. $x + 35=50$, so $x = 15$. Substitute $x = 15$ into $y=-x + 35$, we get $y=-15 + 35=20$. The intersection point of $y=-x + 35$ and $x = 0$ is $(0,35)$. The intersection point of $y=-2x + 50$ and $x = 0$ is $(0,50)$. The intersection point of $y=-2x + 50$ and $y = 0$ is $2x=50$, so $x = 25$ and the point is $(25,0)$.
Step6: Evaluate the cost function at the corner - points
- At $(0,50)$: $C=75\times0+40\times50=2000$.
- At $(15,20)$: $C=75\times15 + 40\times20=1125+800=1925$.
- At $(25,0)$: $C=75\times25+40\times0=1875$.
- At $(0,35)$: $C=75\times0+40\times35 = 1400$. But $(0,35)$ does not satisfy $2x + y\geq50$ ($2\times0+35=35\lt50$).
Answer:
The point $(25,0)$ represents the optimal number of TV - sets and DVD - players that her team should refurbish each week to minimize costs.