Question

A line passes through the points (–3, –4) and (6, 2).

What is the x-intercept of this line?

Answer 1

We can find out the equation of the line by using the slope formula because we already know two points on the line:

(

3

,

0

)

(the

x

-intercept) and

(

5

,

4

)

.

⇒

m

=

y

2

−

y

1

x

2

−

x

1

⇒

m

=

4

−

0

5

−

3

⇒

m

=

4

2

⇒

m

=

2

Now, using point-slope form, we can use the slope and the points that we know to create an equation for the line.

⇒

y

−

y

1

=

m

(

x

−

x

1

)

⇒

y

−

4

=

2

(

x

−

5

)

You could leave it like this, or you could convert it to slope-intercept form by expanding a little further:

y

−

4

=

2

(

x

−

5

)

y

−

4

=

2

x

−

10

y

=

2

x

−

6

Answer 2

The x intercept of this line is 2.