Question

Elena agrees to finish a knitting project for a friend. The graph shows the number of rows Elena completes compared to the amount of time spent knitting.


Assuming she worked at a constant rate, how many rows had been completed before Elena started working?

12
14
15
19

Answer 1

I can’t see the graph you mean — could you upload it or tell me the coordinates of two points on the line (for example, (time, rows) pairs)?

How to find the answer once you have the graph:
1. Pick two clear points on the line, (x1,y1) and (x2,y2).
2. Compute the rate (slope) m = (y2 − y1) / (x2 − x1).
3. Use one point to solve for the intercept b in y = m x + b: b = y1 − m x1.
4. b is the number of rows completed before Elena started (the value at time 0).

If you give me two points from the graph I’ll compute b and pick the matching choice.