Compare Graphs/Tables/Equations

Comparing Graphs/Tables/Equations

How do you know if something is proportional between x and y?

-Graph: it must pass through the origin (0,0) and be a straight line

-Table: it must be a multiplicative relationship to get from x to y

-Equation: you cannot have an additive relationship....example: y = mx + b is NOT proportional; y = x -5 is NOT proportional; y = 2/3x IS proportional

Multiple Choice

Which table shows a proportional relationship between x and y?

Multiple Select

Select the three choices that show a proportional relationship between x and y.

• y = 5/6x

• y=3/8x + 2

Multiple Choice

Which graph shows the equation y = x + 2?

​Do points sit on a line?

To figure out if points sit on a line, plug in the x values from each coordinate pair into the equation. You will get a y value. If the y value matches what is written in the coordinate pair, then yes, it will fall on the line.

For example, in y = 3x - 2, the coordinate pair (5, 13) is on the line, but (-2, 8) is NOT on the line.

Multiple Select

The equation of a line is y = -4x +2. Select all points that are on the line.

• (0, 2)

• (-1, -6)

• (-2, 8)

• (-3, 14)

• (0.5, 0)

​To figure out which table matches an equation...

Plug in the x values into the equation and see if the input/output table works.

If the equation is y = x + 5, this table would NOT work.

Multiple Choice

Which table matches the equation y = -2x - 3?

Multiple Choice

Which table contains values for the equation y = x - 1 ?

Multiple Choice

Which equation matches the table?

• y = -2x

• y = x + 18

• y = 2x + 24

• y = x + 22

​To figure out which table matches a graph...

Test x and y values (they make coordinate pairs) on the graph

This table may have coordinate pairs of (0, 1),
(2, 2), (4, 3), and (-2, 0).

Multiple Choice

Which table matches the graph?

​To figure out what number is missing...

Figure out the equation that shows the relationship between x and y. Then, plug in x or y into the equation (whichever one you have to find what is missing).

​Connect tables, graphs, and equations

Use all of the skills you have learned to far to answer the next question!

Use coordinate pairs. Think of input/output tables as coordinate pairs. The x and y's correspond to each other if they are next to each other (in the same row).

Multiple Select

Identify the three representations that describe the relation shown in the table below.

• y = 3x + 9

• y = x + 5

• {(-2, 3), (-1, 6), (0, 9), (1, 12), (2, 15)}