IXL | Interpret the slope and y-intercept of a linear function

Emma, a construction worker, is lowering a steel beam with a crane. The beam's height decreases as Emma lowers it.

This situation can be modeled as a linear relationship.

What does the slope of the line tell you about the situation?

The beam's height decreases 6 feet per minute.

The beam's height decreases 18 feet per minute.

The beam's height decreases 90 feet per minute.

The beam's height decreases 120 feet per minute.

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Learn with an example

question

Mr. Baker, the owner of Buzz Bee's Bakery, made a large batch of honey-lavender cookie dough. He pulled equal-sized balls of dough from the batch to form the cookies. The amount of dough Mr. Baker has left depends on how many cookies he has formed.

This situation can be modeled as a linear relationship.

What does the

-intercept

of the line tell you about the situation?

Mr. Baker baked 40 cookies.

Mr. Baker made 108 ounces of cookie dough to start.

Mr. Baker used 2 ounces of cookie dough to form each cookie.

Mr. Baker used 12 ounces of cookie dough to form each cookie.

key idea

The

-intercept

of a line is the value of

where the line crosses the

-axis.

It is the

-value

when

solution

To determine what the

-intercept

tells you about the situation, first find the

-intercept.

Look for the point where the line intersects the

-axis.

The line intersects the

-axis

(

108

)

This point tells you that when Mr. Baker had formed 0

cookies,

or when he had all the dough he made to start, Mr. Baker had 108 ounces of cookie dough.

So, this statement is what the

-intercept

tells you about the situation:

green checkmark, Mr. Baker made 108 ounces of cookie dough to start.

These statements are not what the

-intercept

tells you about the situation:

red X symbol, Mr. Baker baked 40 cookies.

The graph tells you how much dough Mr. Baker had left depending on how many cookies he had formed. It does not tell you how many cookies Mr. Baker baked.

red X symbol, Mr. Baker used 2 ounces of cookie dough to form each cookie.

This statement is true, but this is what the slope, , tells you about the situation.

red X symbol, Mr. Baker used 12 ounces of cookie dough to form each cookie.

This statement is not true. The slope, , tells you that Mr. Baker used 2 ounces of cookie dough to form each cookie.

Looking for more? Try these:

Lesson: Linear functions

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Work it out

Not feeling ready yet? These can help:

CC.6Rate of change of a linear function: graphs

CC.4Interpret points on the graph of a linear function

Lesson: Linear functions

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