What you’ll learn
Write line from point and slope.
Key idea
The observed point has nonzero input, so its output need not be the intercept.
Meeting the point alone or the rate alone is insufficient; copying total as fee misses the point.
Worked example
Enter the exact value or ordered values in the format requested below.
A rental total y dollars increases $2 per hour x; at 1 hours the total is $8. Write the full linear model.
- The rate fixes slope 2; the point is (1,8).
- Use 8=2(1)+b, giving b=6; y=2x+6 has the supplied rate and total.
Answer: y=2x+6
Quick Check
Choose which candidate representation satisfies the requirements of 'Write line from point and slope' and justify the choice.
A rental total y dollars increases $2 per hour x; at 1 hours the total is $13. Select with BOTH rate and point evidence.