Algebra 1 : Parallel Lines

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #41 : Parallel Lines

If line X is parallel to line A with a slope of  and a y-intercept of , what is the slope of line X?

Possible Answers:

Not enough information 

Correct answer:

Explanation:

By definition, lines are parallel if they have the same slope.

The problem states that line A has a slope of  and that line X is parallel to it.

This means that line X must also have a slope of .

The y-intercept is not a determinant of lines being parallel or perpendicular.

Example Question #42 : Parallel Lines

If a line is parallel to the line , what must be the slope of the other line?

Possible Answers:

Correct answer:

Explanation:

If a line is parallel to another line, they will never intersect.  This means that their slopes will be the same.

The equation given is in standard form.  Convert the equation to slope intercept form, , in order to determine the slope .

Subtract  on both sides.

Simplify and reorganize the terms.

Divide by three on both sides.

Simplify both sides.

The slope of the parallel line must be .

Example Question #41 : Parallel Lines

What is the slope of a line that is parallel to ?

Possible Answers:

Correct answer:

Explanation:

To find the slope of a line parallel to any equation, the slopes will always be the same. We need to ensure we have  form.  stands for slope. In this case,  which is also our answer.

Example Question #22 : How To Find The Slope Of Parallel Lines

What is the slope of a line that is parallel to ?

Possible Answers:

Correct answer:

Explanation:

When finding the slope of a parallel line, we need to ensure we have  form. 

 

We need to solve for .

By adding  both sides and dividing  on both sides, we get    stands for slope.

Our  is   which is also the slope of the parallel line.

Example Question #23 : How To Find The Slope Of Parallel Lines

What is the slope of a line that is parallel to 

Possible Answers:

Correct answer:

Explanation:

When finding the slope of a parallel line, we need to ensure we have  form. 

 

We need to solve for .

By subtracting  both sides and dividing  on both sides, we get 

  

Recall that  stands for slope.

Our  is  or  which is also the slope of the parallel line.

Example Question #24 : How To Find The Slope Of Parallel Lines

Find the slope of a line parallel to a line with the equation:

Possible Answers:

Correct answer:

Explanation:

When finding the slope of a parallel line, the slope will be the same as the other equation given. 

In order to determine the slope from an equation we need to make sure that it is written in the following format:

If the equation of a line is written in the slope-intercept form, then  is slope and  is the y-intercept.

In this case, the slop is .  This is also the slope of the parallel line. 

Example Question #25 : How To Find The Slope Of Parallel Lines

Find the slope of a line parallel to a line with the equation:

Possible Answers:

Correct answer:

Explanation:

When finding the slope of a parallel line, the slope will be the same as the other equation given. 

In order to determine the slope from an equation we need to make sure that it is written in the following format:

If the equation of a line is written in the slope-intercept form, then  is slope and  is the y-intercept.

In this case, we need to convert the equation into slope-intercept form.

 

Subtract  from both sides.

 

Divide both sides by .

 

Rewrite.

Identify the slope.

The slope is  or . This is also the slope of the parallel line.

Example Question #26 : How To Find The Slope Of Parallel Lines

Find the slope of a line parallel to a line with the equation:

Possible Answers:

Correct answer:

Explanation:

When finding the slope of a parallel line, the slope will be the same as the other equation given. 

In order to determine the slope from an equation we need to make sure that it is written in the following format:

If the equation of a line is written in the slope-intercept form, then  is slope and  is the y-intercept.

In this case, we need to convert the equation into slope-intercept form.

 

Divide both sides by .

 

Identify the slope.

The slope is . This is also the slope of the parallel line.

Example Question #1 : How To Find Out If Lines Are Parallel

Which of the following lines are parallel to y = 2x + 5? 

Possible Answers:

y = 4x + 3

y = –2x + 8

y = 2x – 3

y = 6x + 5

y = (–1/2)x + 6

Correct answer:

y = 2x – 3

Explanation:

Lines are parallel if they have the same slope. The lines are all given in the form y = mx + b. In this form, m represents the slope, thus, we are looking for another line with a slope of 2. This is y = 2x – 3. 

Note that the line given by y = (–1/2)x + 6 has a slope that is the negative reciprocal of 2. This line will be perpendicular to our given line.

Example Question #42 : Parallel Lines

True or False.

The following two lines are parallel.

Possible Answers:

True

False

Correct answer:

True

Explanation:

When both equations are solved for the form  the slopes are the same.

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