Tables and graphs

PLOTTING STRAIGHT LINES

​Learning goals:

To understand that a straight-line graph is formed from a linear rule

To be able to plot a graph of a rule using a table of values

To be able to use a straight line graph to determine the values of variables

​Key ideas

​Let's practice

3 questions follow to check understanding.....

Multiple Choice

The table shows the x and y values for the equation

y = x - 6.

What is the missing number?

• 12

• 10

• 14

• 13

Multiple Choice

The table shows the x and y values for the equation

y = 2x + 1.

Find the missing y value.

• -2

• 3

• 9

• -7

Multiple Choice

The table shows the x and y values for the equation

y = 9x - 1.

Find the missing y value.

• -19

• 17

• 19

• 17

Can you find the rule and missing number?

Can you find the rule and missing number?

​3 questions to check understanding ....

​9 questions follow to check understanding.....

Multiple Choice

What is the rule (equation) for this table?

• y = x + 5

• y = 5x

• y = x - 5

• y = x - 5

Multiple Choice

What is the rule (equation for this table?

• y = 480x

• y = x + 479

• y = x + 480

• y = 480 - x

Multiple Choice

Which table is correct for y=4x+3?

Multiple Choice

Which equation matches the table?

• y = x 
• y = 5x
• y = x - 4
• y = x + 4

Multiple Choice

Find the equation of the line

• y = 16x

• y = 2x +2

• y = -2x -2

• y = 4x + 0

Multiple Choice

Find the equation of the line

• y =4x + 1

• y = 3x -1

• y = 8x +11

• y = 12x + 56

Multiple Choice

Find the equation of the line

• y = 4x + 2

• y = 2x + 3

• y = 3x - 1

• y = 3x + 6

Multiple Choice

Three tables of values are shown.

Which table shows the x and y values for the equation

y = x + 5?

• a

• b

• c

Multiple Choice

When a rule is written as a sentence:

The cost to hire a car from Easy Car Rental is $8.50 an hour plus a rental fee of $25.50.

• c = 8.5 + 25.5

• c = 25.5 + 8.5x

• c = 8.5 + 25.5x

​To find the y-intercept (c), substitute a coordinate pair into the equation.

Let's do this.

​Now you try. Find the equation for this data.

​2 questions follow to check understanding.....

Multiple Choice

Which equation describes the table shown?

• y = x + 2

• y = x - 2

• y = 2x + 1

• y = -2x + 2

Multiple Choice

Which equation matches the table?

• y = x + 8

• y = 2x + 3

• y = x + 10

• y = 3x - 4

​When we know the gradient and y-intercept, we can graph our line.

​And if we have a graphed line, we can find the equation.

​Let's practice.

​What are the equations of these lines?

​5 questions follow to check understanding.....

Multiple Choice

Which is the graph of the equation y = -3x - 1?

Multiple Choice

Which graph represents the table?

Multiple Choice

Which line is being represented by the graph?

• y = 3/4 X -3
• y = -3/4x + 4
• y = 3/4x + 4
• y = -3/4 x - 3

Multiple Choice

Which company shows a greater rate of change (gradient)?

• Water's Edge Rafts
• Ryan's Rafts

Multiple Choice

Which graph represents the table?

​If we graph 2 lines together, we get a point of intersection where they cross over.

5 questions follow to check understanding.....

Multiple Choice

What is the point of intersection?

• (-2, -2)
• (2, -2)
• (-2,2)
• (2, 2)

Multiple Choice

What is the point of intersection?

• (2.5, 1)
• (1, 2.5)
• (-2.5, -1)
• (-1, -2.5)

Multiple Choice

What is the point of intersection?

• (2, 0)
• (-2, 0)
• (0, 2)
• (0, -2)

Multiple Choice

What is the point of intersection?

• (-3, 0)
• (0, 3)
• (3, 0)
• (0, -3)

Multiple Choice

What is the point of intersection?

• (-1, -2)
• (-1, 2)
• (1, 2)
• (1, -2)

​To summarise:

​3 questions follow to check whether our learning goals have been achieved.....

Poll

How well do you understand that a straight-line graph is formed from a linear rule?

Poll

Are you able to plot a graph of a rule using a table of values?

Poll

Can you use a straight-line graph to determine the values of variables?