Additive Relationships

Additive Relationship

Additive Relationship

• In an Additive Relationship you ADD or SUBTRACT the same quantity to the independent quantity, x, to get the dependent quantity, y.

• Does NOT cross the origin, (0,0).

• RULE: y = x + a

• a = begin the number being added or subtracted to the independent quantity.

Multiple Choice

Additive relationship is where you add or subtract x and any quantity in order to find y.

• True

• False

Multiple Choice

What is the correct equation for an additive relationship?

• y = x+a

• x = y+a

• y = ax

• a/x = m

Example

Owen is two years older than his sister Greta.

Think: Greta's Age + 2

Greta's Age = X

Owen's Age = Y

RULE: y = x + 2

When Greta is 5, Owen will be 7.

y = (5) + 2 = 7

HINT

When looking at a graph, look where the line crosses the y-axis

The constant in an additive equation tells you where it will cross.

So, if a line crosses the graph at a positive 5, then the additive relationship between x and y for this graph is:

y = x + 5

Multiple Choice

Which of the following best represents the equation y = x - 2?

• y is 2 minus x

Multiple Choice

Given the table of values for the additive relationship, what is the equation of the line in $$y=x+a$$  form? 

• $$y=x-1$$  

• $$y=x+1$$  

• $$y=x+3$$  

• $$y=x-5$$  

Multiple Choice

A relationship is represented by y = x - 16. Which table best represents the equation?

Multiple Choice

Which of the equations below match the graph?

• $$y=4x$$

• $$y=x+4$$

• $$y=x-4$$

• $$y=-4x$$

Multiple Choice

Apples weighing 30 pounds are placed in a crate that weighs p pounds. Which equation can be used to find t, the total weight of both the crate and the apples in pounds?

• t = 30p

• t = p + 30

• p = t + 30

• t = 30 - p