1. **State the problem:**
We are given data points for $x$ and $y$ and asked to draw the graph of $y$ against $x$ for $0 \leq x \leq 15$ (part c), and to find a possible value of $k$ such that Alex breaks even within 10 to 15 months (part d).
2. **Recall the function from part (b):**
From the data points $(1,3)$, $(5,5)$, and $(10,10)$, we find the function $y$ in terms of $x$.
3. **Find the function $y=f(x)$:**
Calculate the rate of change (slope) between points:
Between $(1,3)$ and $(5,5)$:
$$m=\frac{5-3}{5-1}=\frac{2}{4}=0.5$$
Between $(5,5)$ and $(10,10)$:
$$m=\frac{10-5}{10-5}=\frac{5}{5}=1$$
Since slopes differ, the data is not perfectly linear, but for simplicity, assume a linear function passing through $(0, y_0)$ and $(10,10)$.
Using points $(0,y_0)$ and $(10,10)$:
Assuming $y_0$ is the initial cost at $x=0$, from the problem setup, initial cost is $20,000$ (equipment and renovation), but the table shows $y$ values as 3,5,10 which likely represent thousands or a simplified scale.
Given the problem context, the total cost function is:
$$y = 20000 + 6000x$$
4. **Part (c) Draw the graph:**
Plot the linear function:
$$y = 20000 + 6000x$$
for $x$ from 0 to 15.
5. **Part (d) Find $k$ for break-even:**
Break-even means total income equals total cost.
Total cost after $x$ months:
$$y = 20000 + 6000x$$
Total income after $x$ months:
$$kx$$
Set income equal to cost:
$$kx = 20000 + 6000x$$
Rearranged:
$$kx - 6000x = 20000$$
$$x(k - 6000) = 20000$$
$$k - 6000 = \frac{20000}{x}$$
$$k = 6000 + \frac{20000}{x}$$
Since Alex wants to break even between 10 and 15 months, choose $x=10$:
$$k = 6000 + \frac{20000}{10} = 6000 + 2000 = 8000$$
Or $x=15$:
$$k = 6000 + \frac{20000}{15} \approx 6000 + 1333.33 = 7333.33$$
So a possible value of $k$ is any number between approximately 7333.33 and 8000.
**Final answers:**
- (c) Graph of $y = 20000 + 6000x$ for $0 \leq x \leq 15$.
- (d) Possible value of $k$ is between 7333.33 and 8000.
C D Break Even D2Ed38
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