How can you find the equation of a line that is parallel/perpendicular to a given line

In the Slope-Intercept Form, m is the slope and b is the y-intercept.

Finding The Equation of a Line Parallel to the Given Line: Let the given line be line a and the parallel line be line b.

1) Find the slope of line a.

Example: Line a --> . The slope is 5.

2) Find the y-intercept of line b.

To do this, you need to be given the coordinates of a point located on line b.

Example: The slope is 5 and the point is (2, 3), use the Slope-Intercept Formula, ---> . Then you solve for b.

The y-intercept of line b is -7

3) Finally, plugin the slope and the y-intercept into the Slope-Intercept Form.

Example: The slope of line b is 5 and the y-intercept is -7. The equation of line b is .

Finding The Equation of a Line Perpendicular to The Given Line: Let the given line be line a and the perpendicular line be line b.

1) Find the opposite reciprocal of the slope of line a.

Example: Line a --> . The slope is 5, to find the opposite reciprocal of the slope you use n --> . In this case, it would be . The opposite reciprocal of the slope of line a is , which would be the slope of line b.

2) Find the y-intercept of line b.

To do this, you need to be given the coordinates of the point where line a and line b both intersect.

Example: The slope of line b is and the point is (1, 7), use the Slope-Intercept Formula, ---> . Then you solve for b.

The y-intercept of line b is .

3) Finally, plugin the slope and the y-intercept into the Slope-Intercept Form.

Example: The slope of line b is and the y-intercept is . The equation of line b is .

since we know that the two functions are equal, f (x) = g

(x), therefore when we equate the two equations the result should be similar to

3x = x – 4:

a. f(x) = 3x, g(x) = x – 4

equating the two functions:

3x = x – 4             (correct)

so we now got our answer (a)