Your parabola should look like this image. The vertex is at (-1, 9), and you can use any of the x-intercepts (-4, 0) & (2, 0) or the y-intercept (0, 8) as a second point.
Answer:
b. A year and a half
Step-by-step explanation:
First, we can find the total cost

Next, we can divide by 50 in order to find out how many months it will take for the panel to pay for itself.
months
This is very close to 36 months, which is <u>A year and a half</u>.
1/8 of anything is just 1/8 * anything, so