# High School Math : How to identify a point in pre-algebra

## Example Questions

### Example Question #1 : How To Identify A Point In Pre Algebra

What is the slope of the line .

Explanation:

In the standard form of a line  the slope is represented by the variable .

In this case the line  has a slope of .

### Example Question #1 : How To Identify A Point In Pre Algebra

If the equation of a line is , what is the y-intercept?

Explanation:

In the slope-intercept form of a line, , the y-intercept when the line intersects the y-axis.

It does this at .

So we plug  in for  in our equation  to give us .

Anything multiplied by  is  so .

Our coordinates for the y-intercept are .

### Example Question #1 : How To Identify A Point In Pre Algebra

What is the y-intercept of the line ?

Explanation:

In the standard form of a line  the y-intercept occurs when the line intersects the y-axis.

It does this at

So we plug  in for  in our equation  to give us .

Anything multiplied by  is  so .

Our coordinates for the y-intercept are .

### Example Question #1 : How To Identify A Point In Pre Algebra

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

Explanation:

Parallel lines have the same slope.

If an equation is in point-slope form, , we take the  from our equation and set it equal to the slope of our parallel line.

In this case

The slope of our parallel line is .

### Example Question #1 : How To Identify A Point In Pre Algebra

Define the point based on the coordinate plane.

Explanation:

The point resides in quadrant I (the upper right quadrant), so both values must both be positive. The only possible solution is .

### Example Question #6 : How To Identify A Point In Pre Algebra

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

Explanation:

The slope of a perpendicular lines has the negative reciprocal of the slope of the original line.

If an equation is in point-slope form, , we use the  from our equation as our original slope.

In this case

First flip the sign to get

To find the reciprocal you take the integer and make it a fraction by placing a  over it. If it is already a fraction just flip the numerator and denominator.

Do this to make the slope

The slope of the perpendicular line is .

### Example Question #1 : Graphing

What is the slope of the line with the equation ?

Explanation:

In the standard form equation of a line, , the slope is represented by the variable .

In this case the line  has a slope of .

### Example Question #2 : How To Identify A Point In Pre Algebra

What is the slope of the line ?

Explanation:

In the slope-intercept form of a line, , the slope is represented by the variable .

In this case the line

has a slope of .

### Example Question #1 : Graphing Lines

What is the y-intercept of the line ?

Explanation:

In the slope-intercept form of a line, , the y-intercept is when the line intersects the y-axis.

It does this at .

So we plug  in for  in our equation

to give us

Anything multiplied by  is  so

Our coordinates for the y-intercept are .

### Example Question #1 : How To Identify A Point In Pre Algebra

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