ALG STAAR Review - Linear Functions

Algebra I

STAAR REVIEW

Linear Functions

Y-intercept

The point where the graph intersects or crosses the y-axis.

●Written as (0, y-value)

●The point where x=0

Multiple Choice

The y-intercept is the point where the line intersects the ___________.

• y -axis

• x-axis

X-intercept

The point where the graph crosses the x axis.

●Written as (x-value, 0)

●The point where y=0

Multiple Choice

The x-intercept is the point where the line intersects the ___________.

• y -axis

• x-axis

Points (on a graph)

A point is always written in the form ( x , y ).

-X-Coordinate:

●To the right: Positive

●To the left: Negative

-Y-Coordinate:

●Above x-axis: Positive

●Below x-axis: Negative

Multiple Choice

What are the coordinates of Point A?

• (-2,3)

• (2,3)

• (3,2)

• (3,-2)

Multiple Choice

The coordinates of the x-intercept are:

• (-2,0)

• (0,2)

Multiple Choice

The coordinates of the y-intercept are:

• (-2,0)

• (0,2)

Practice Problem:

Y-intercept = ( 0 , ___ )

X-intercept = ( ____ , 0 )

Slope = Rate of Change

The value (sign and number) that describes both the direction and the steepness of
a straight line.

●Hint words: per, each, and every

(if you see these words in a word problem

it usually means slope)

●Examples of slope:

○Miles per hour (the speed limit is 25 MPH)

○Hourly pay (Jose earns $18 every hour)

Rise / Run (Rise over run)

Strategy to find slope on a graph.

Identify two points. Count up (+) or down (-); put value on the top of the fraction.
Count right (+) or left (-); put value on the bottom of the fraction.

Multiple Choice

The slope of the line is _______.

• -3/1

• 3/1

• -1/3

• 1/3

Multiple Choice

What is the rate of change of this line?

• 3/1

• -3/1

• 1/3

• -1/3

Multiple Choice

What is the rate of change of this line?

• +2/3

• 3/2

• -2/3

• -3/2

Slope-intercept form y = mx + b

SLOPE-INTERCEPT FORM is the equation of a straight line in the form y = mx + b
where m is the slope of the line and b is its y-intercept.

Multiple Choice

What is the y-intercept of the line y = 5x + 3

• 5

• 3

• 3/5

Multiple Choice

What is the rate of change of the line y = 1/2x + 3

• 3/2

• 3

• 1/2

Linear function

A function that graphs as a straight line.

●Decreasing if the slope is negative

●Increasing if the slope is positive

●Vertical line slope is undefined

●Horizontal line slope is zero

Dropdown

This line represents ​

Select answer

slope.

Dropdown

This line represents ​ ​

Select answer

slope.

STAAR Question:

Finding slope or rate of change

Desmos Skill:

Line 1: Click +Table

Line 2: Enter y1 ~ mx1 + b Demos will calculate m= and b=

Multiple Choice

• -8/5

• -5/8

• 8/5

• 5/8

STAAR QUESTION:

*Use x as your variable in Desmos*
(Replace n with x.)

Solve

What is the solution…

Which value of x makes the equation true…

What is the value of y when x= …..

Which is best represented by…….

ALL mean solve
- or to find the
solution to the
problem

Multiple Choice

• 3

• -9

• 0

• -15

STAAR QUESTION:

Find x when y =

Desmos skill:

Find the solution by the equation in desmos line 1. Then put the given y
value in line 2. The x value where the line cross is the solution.

Multiple Choice

• -35/4

• -55/4

• 35/4

• 55/4

Formula Chart

Practice STAAR Questions:

Posted on Google Classroom -

4/27: Linear Functions Practice