1. Solve it yourself
If x = 3, what is the value of y in y = 2x + 4?
Task 1 of 12
Meet Desmos
2. Check in Desmos
Desmos is a graphing calculator. The panel on the left is where you type. Each line is an expression or an equation, and Desmos draws the graph.
- Type y=2x+4
- Type x=3
- Click the grey point where the lines meet.
- Type the y-value in the answer box below.
Loading Desmos…
Loading Desmos…
Task 2 of 12
Graph an equation
1. Solve it yourself
The equation is y = 3x − 2. Where does the line cross the y-axis? Write the y-value.
2. Check in Desmos
- Type y=3x-2
- Look at where the line crosses the y-axis.
- Answer the question under the graph.
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Does the line cross the y-axis at −2?
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Task 3 of 12
Same line
1. Solve it yourself
Are 2(x + 3) and 2x + 6 equivalent? Write yes or no, and how you know.
2. Check in Desmos
If two expressions lead to the same result, they are called equivalent. One way to check this is by graphing them as equations and checking if they make the same line.
- On line 1, type y=2(x+3)
- On line 2, type y=2x+6
- Look at the graph.
- Answer the question under the graph.
Loading Desmos…
Do they make the same line?
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Task 4 of 12
Two different lines
1. Solve it yourself
Are 3x + 2 and 3x + 5 equivalent? Write yes or no, and how you know.
2. Check in Desmos
- On line 1, type y=3x+2
- On line 2, type y=3x+5
- Look at the graph.
- Answer the question under the graph.
Loading Desmos…
Do they make the same line?
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Task 5 of 12
A line from a table
1. Solve it yourself
Write an equation (in y=ax+b form) that represents the data in the following table.
| x | y |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 7 |
| 3 | 10 |
2. Check in Desmos
- A table is already open.
- In the x column, type 0, 1, 2, and 3.
- In the y1 column, type 1, 4, 7, and 10.
- Type the equation you found. Start it with y=
- Answer the question under the graph.
Loading Desmos…
Does your line pass through every point?
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Task 6 of 12
Finding an Equation
1. Solve it yourself
Write the equation you expect, in y = ax + b form.
| x | y |
|---|---|
| 0 | 3 |
| 1 | 5 |
| 2 | 7 |
| 4 | 11 |
2. Check in Desmos
- Click the first line.
- Type table and press enter.
- In the x column, type 0, 1, 2, and 4.
- In the y1 column, type 3, 5, 7, and 11.
- Under the table, click the regression icon. It looks like points with a line through them.
- Read a and b.
- Type the equation y = ax + b.
Loading Desmos…
Loading Desmos…
Task 7 of 12
A taxi fare
1. Solve it yourself
A taxi costs $4 plus $2 per kilometre. Complete the table. Write the four costs.
| km | 0 | 1 | 2 | 5 |
|---|---|---|---|---|
| cost ($) | ? | ? | ? | ? |
2. Check in Desmos
- A table is already open.
- In the x column, type 0, 1, 2, and 5. These are the kilometres.
- In the y1 column, type the four costs you found.
- Answer the question under the graph.
Loading Desmos…
Does your table show those four costs?
Loading Desmos…
Task 8 of 12
Graph the taxi fare
1. Solve it yourself
The same taxi costs $4 plus $2 per kilometre. Write an equation for the cost. Use x for kilometres and y for cost.
2. Check in Desmos
- The table from the taxi story is already on the graph.
- Type y=2x+4
- Answer the question under the graph.
Loading Desmos…
Does the line pass through every point in the table?
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Task 9 of 12
Slope and a point
1. Solve it yourself
A line has slope 2 and passes through (1, 5). Write its equation in the form y = mx + b.
2. Check in Desmos
- The point (1, 5) is already on the graph.
- Type your equation. Start it with y=
- Answer the question under the graph.
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Does your line pass through (1, 5)?
Loading Desmos…
Task 10 of 12
Shipping cost
1. Solve it yourself
Sometimes you may come across numbers that make it really challenging to figure out the equation. In these cases, Desmos is extremely valuable.
Write an equation in y = ax + b form. Use x for kilograms and y for cost.
| Mass (kg) | Cost ($) |
|---|---|
| 2 | 5.60 |
| 5 | 13.10 |
| 9 | 23.10 |
| 11 | 28.10 |
2. Check in Desmos
- Click the first line.
- Type table and press enter.
- In the x column, type the masses 2, 5, 9, and 11.
- In the y1 column, type the costs 5.60, 13.10, 23.10, and 28.10.
- Under the table, click the regression icon. It looks like points with a line through them.
- Read a and b.
- Type the equation y = ax + b.
Loading Desmos…
Loading Desmos…
Task 11 of 12
Check your understanding
Answer all six questions, then select Mark Answers. You need all six correct to continue.
Task 12 of 12
Scooter rental
1. Solve it yourself
A scooter rental costs $8 plus $2 per hour. After how many hours is the cost $20?
2. Check in Desmos
- Use x for hours and y for cost.
- Graph the cost as y=2x+8
- Graph y=20
- Click the grey point where the lines meet.
- Type the number of hours.
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Loading Desmos…