Algebra 1 : Slope and Line Equations

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #111 : How To Find Slope Of A Line

Find the slope of the line that travels through the points  and .

Possible Answers:

Correct answer:

Explanation:

To find the slope of a line that travels through any two points, we always use the same formula:

Any time we are given a set of points on a line, they are written out as follows: . The  value is always listed first, followed by the y value. 

When you are given two sets of points, you can find the slope of the line that travels through the by plugging in the values you were given into the slope formula. Let's try it ourselves. 

Pick one of the two sets of points that you were given as your starting point. It doesn't matter which set you start with, so let's use . is an  value, and  is a  value; since this is the first set we chose, let's say  is , and  is . Let's plug these two values into our formula for now:

Now, let's fill in the rest of the formula with the values from our set set of points, .

Since we're using this set second,  will be , and -3 will be :

Now, we just need to simplify:

 

So, the slope of our line is

 

**Remember, it doesn't matter which set of points you use first or second, as long as you make sure you do not mix up the order that you use the values in. For example, if you used  as , you MUST use  as , NOT . Values that come from the same set of points must be used to replace variables with the same sub-value.

Example Question #113 : How To Find Slope Of A Line

Find the slope of a line that connects points  and .

Possible Answers:

Correct answer:

Explanation:

The formula for the slope of a line is .

All we need to do is plug in our values and solve for m.

Therefore, to solve, we get

Example Question #114 : How To Find Slope Of A Line

A line passes through the points  and . What is the slope?

Possible Answers:

Correct answer:

Explanation:

The slope of a line is a measure of the rate of change of the incline of a line. Slope is more commonly taught as "rise over run". This kind of problem can be easily solved for by using the simple formula for slope. 

, where  denotes slope. Rise denotes change in the y-axis where run denotes change in the x-axis. This makes sense because rise indicates a vertical change while run indicates a horizontal change.

The given points may be arbitrarily assigned as  and . For this problem we will assign  as  and  as

Therefore, 

Example Question #115 : How To Find Slope Of A Line

A line passes through the points  and . What is the slope of the line?

Possible Answers:

Correct answer:

Explanation:

The slope of a line is a measure of the rate of change of the incline of a line. Slope is more commonly taught as "rise over run". This kind of problem can be easily solved for by using the simple formula for slope. 

, where  denotes slope. Rise denotes change in the y-axis where run denotes change in the x-axis. This makes sense because rise indicates a vertical change while run indicates a horizontal change.

The given points may be arbitrarily assigned as  and . For this problem we will assign  as  and  as

Therefore, 

Example Question #116 : How To Find Slope Of A Line

If a line passes through the points  and , what is its slope?

Possible Answers:

Correct answer:

Explanation:

The slope of a line is a measure of the rate of change of the incline of a line. Slope is more commonly taught as "rise over run". This kind of problem can be easily solved for by using the simple formula for slope. 

, where  denotes slope. Rise denotes change in the y-axis where run denotes change in the x-axis. This makes sense because rise indicates a vertical change while run indicates a horizontal change.

The given points may be arbitrarily assigned as  and . For this problem we will assign  as  and  as

Therefore, 

Example Question #117 : How To Find Slope Of A Line

What is the slope, , of the line:  

 

Possible Answers:

Correct answer:

Explanation:

To solve this question you must get the equation written in the   formula.

To do this, you need to isolate the  by dividing everything by . So you will get:

 in the slope-intercept equation is your slope, which in this equation is .

Example Question #181 : Slope And Line Equations

Find the slope and y intercept of the following function:

Possible Answers:

Correct answer:

Explanation:

The easiest way to solve this porblem is to change it into slope-intercept form:

 

where m is slope and b is the y intercept.

Combining like terms and isolating y:

Now our function is ins slope-intercept form and we can see that:

.

 

 

 

Example Question #119 : How To Find Slope Of A Line

A function is given as 

.

Find the slope and the y-intercept of this function. 

Possible Answers:

None of the above. This is not a linear function.

Correct answer:

Explanation:

The original function is is given in standard form, 

.

Convert this equation into slope-intercept form, 

.

 

First subtract 3x from each side.

Now divide by negative two to solve for y.

In slope intercept form the equation becomes, 

.

We know that, in slope-intercept form, the slope is given as "m" while the y-intercept is given as "b".

Therefore, the slope of this function is  and the y-intercept is .

Example Question #120 : How To Find Slope Of A Line

Nikki is a physicist interested in understanding the relationship between temperature, T, and some electrical property, Q. She realizes that  when  and  when . Choose the best estimate of the value of Q when  .

(Assume the relationship between Q and T is linear.)

Possible Answers:

Correct answer:

Explanation:

Since we were told to consider the relationship of Q vs. T as a line, this problem falls into the category of liner interpolation problems. That being said, familiarity with linear behavior is the only requirement to successfully handle this problem.

First we should use the two given points to find the slope of this line as: 

.

Realize, that the function of interest is a line, so the slope between any two points must be the same. With this in mind, we can write an equation that describes the slope between the new point (where Q is unkown) and the first point:

 

Now, we may simply solve this equation to find the new value of Q that must correspond to the T value of .

Isolating Q in the equation above, one may find that when , the value of Q must be .

Example Question #121 : How To Find Slope Of A Line

Find the slope of the line which passes through the following points:

Possible Answers:

Correct answer:

Explanation:

Find the slope of the line which passes through the following points:

Slope can be found using the following formula:

Now, just plug in the points you are given, making sure to keep them consistent!

So our slope is:

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