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Equation of a Line Given Slope and a Point

How to write the equation

Students are often asked to find the equation of a line that passes through a point and has a certain slope. That is exactly what we will learn how to do today !

Video Tutorial on Equation from Slope and a Point

Example Problem

Find the equation of a line that goes through the point (1, 3) and has a slope of 2.

Step 1

Substitute slope for 'm' in y = mx + b.

y=mx+by=2x+b

Step 2

Substitute the point (1,3) into equation.

y=2x+b3=2(1)+b

Step 3

Solve for b.

3=2+b32=1=b

Step 4

Now that we know b, all that we have to do is substitute it into the equation, and we now have our line in slope intercept form.

y=2x+1

Diagram of Line
Equation of line from its slope and one point

Practice Problems

Directions: For all questions below, express your answers using slope intercept form.
Problem 1

Write the equation of a line that has a slope of 12 and that goes through the point (2,3).

Problem 2

The slope of a line is 10 and the line goes through the point (3,34). Express the equation of this line in slope-intercept form.

Problem 3

The slope of a line is 3 and the line goes through the point (6,23) Express the equation of this line in slope-intercept form.

Problem 4

What is the equation of a line whose slope is 0 and that goes through the point (7,5) ? Express the equation of this line in slope-intercept form.

Back to Slope Intercept Form Next to Worksheet on this topic