Question

Selecting Strategies to Solve
A graph has points (3, 9), (4, 13.5), and (5, 18).

Given the graph of a linear function, identify the steps used to find the initial value. Check all that apply.
Find the rate of change using rise over run.
Find corresponding y values when x = 6, x = 7, and x = 8. Then plot the points to finish the line.
Find corresponding y values when x = 2, x = 1, and x = 0. Then plot the points to finish the line.
The initial value corresponds to the y value when x = 1.
The initial value corresponds to the y value when x = 0.

Answer 1

Choose:
- Find the rate of change using rise over run. (Yes)
- Find corresponding y values when x = 2, x = 1, and x = 0. Then plot the points to finish the line. (Yes)
- The initial value corresponds to the y value when x = 0. (Yes)

Do not choose:
- Find corresponding y values when x = 6, x = 7, and x = 8. Then plot the points to finish the line. (Not needed to get the initial value.)
- The initial value corresponds to the y value when x = 1. (Incorrect — the initial value is the y-intercept at x = 0.)

(If helpful: slope = (13.5−9)/(4−3)=4.5, so y = 4.5x + b. Using (3,9) gives b = −4.5, so the initial value is −4.5.)