The line on the graph passes through point A (1,3) and B (7,1).

If the gradient of the line perpendicular to AB is 3, find the equation of the line passing through point (4,2) and perpendicular to AB.

Janie has $3. she earns $1.20 for each chore she does and can do fractions of chores. she wants to earn enough money to buy a cd for $13.50. write an inequality to determine the number of chores, c, janie could do to have enough money to buy the cd.