Algebra: Linear Relations

Patterns and trends, tables of values, graphs and equations of linear relations, and using them to interpolate and extrapolate.

10 questions, free, marked as you go with a worked explanation on every one.

What this covers

A plumber's bill is a straight-line relation. A 2 hour job costs $140 and a 6 hour job costs $260. What is the hourly rate, in dollars per hour?
Using that same relation, with a 2 hour job costing $140 and a 6 hour job costing $260, what is the plumber's fixed call-out fee, in dollars?
For the relation C = 30h + 80, what does the bill come to for a 9 hour job, in dollars?
In the linear relation C = 30h + 80 describing a plumber's bill, what does the 80 represent?
A fuel tank is draining steadily. It holds 850 L at the start and 690 L after 4 hours. How many litres does it lose each hour?
That same tank starts at 850 L and loses 40 L each hour. How many litres remain after 9 hours?
For that same tank, V = 850 - 40t. After how many hours will the tank be empty?
A table of values for a linear relation shows that y = 17 when x = 3, and y = 32 when x = 8. What is the value of y when x = 0?
A bike rental charges a $4 flat fee plus $2 for every hour. Let x be the hours and y the total cost in dollars. Graph the relation.
On the graph shown, the line meets the vertical axis at 4. In the cost relation y = 2x + 4, what does that 4 represent?