4. there is a new food delivery company that charges $10 to deliver 3 meals and $16 to deliver 12 meals. if…

Explanation:

Step1: Find the cost per meal

First, find the difference in cost and number of meals. The difference in cost is $16 - 10=$6$, and the difference in number of meals is $12 - 3 = 9$. So the cost per meal is $\frac{16 - 10}{12 - 3}=\frac{6}{9}=\frac{2}{3}$ dollars per meal.

Step2: Find the base - cost

Let the cost function be $C = mx + b$, where $C$ is the total cost, $x$ is the number of meals, $m$ is the cost per meal, and $b$ is the base - cost. Using the point $(3,10)$ and $m=\frac{2}{3}$, we substitute into the equation: $10=\frac{2}{3}\times3 + b$. Simplifying gives $10 = 2 + b$, so $b = 8$.

Step3: Calculate the cost for 9 meals

Substitute $x = 9$ into the cost function $C=\frac{2}{3}x+8$. Then $C=\frac{2}{3}\times9 + 8=6 + 8=$14$.

Answer:

$14$