A graph of two jobs sharing one earnings total has a useful intercept: where the line meets an axis, one job has zero hours. Read the other job’s hours there, then multiply by its hourly rate to find the total. Don’t add the earnings from both intercepts. They show different possible weeks, not two parts of one week.
Hints
- Hint 1
An intercept is where the line meets an axis. At the vertical-axis crossing, job A has zero hours. How many hours does the graph show for job B?
- Hint 2
Earnings equal the hourly rate multiplied by hours. Since job A has zero hours at that crossing, job B’s earnings alone equal the total .
Step-by-step
Use the one-job intercept
Step 1Read the hours at the vertical-axis crossing
No Desmos needed. The graph supplies the hours, and the total takes one multiplication. The line crosses the vertical axis at . The axes put job A’s hours first and job B’s second, so Avery worked hours at A and hours at B. With no hours at job A, job B alone earned the whole total.
- Step 2
Find the earnings from those hours
Job B pays $20 per hour, so multiply job B’s rate by its hours to get the total:
Multiply:
The other axis crossing is a different way to earn the same total, not extra hours to add. Avery earned $160 that week. Choice B.