Homework Help

Find the equation of the straight line joining each of the following pairs of points...

user profile pic

aa42 | Student, Grade 10 | (Level 1) Honors

Posted September 27, 2012 at 8:38 PM via web

dislike 2 like

Find the equation of the straight line joining each of the following pairs of points

(a) (0, 0) and (1,-1)

2 Answers | Add Yours

user profile pic

lfryerda | High School Teacher | (Level 2) Educator

Posted September 27, 2012 at 10:26 PM (Answer #1)

dislike 1 like

If you have more than one question, you need to make separate posts.

To find the equation of a line, you need to have the slope of the line and a point on the line.

The slope is found using the slope formula:

`m={y_2-y_1}/{x_2-x_1}`

`={-1-0}/{1-0}`

`={-1}/{1}`

`=-1`

Now sub in the point and slope into the equation y=mx+b to get:

`y=mx+b`

`-1=-1(1)+b`

`-1=-1+b`   move -1 to left side

`-1+1=b`

`0=b`

This means the equation of the line is `y=-x` .

user profile pic

salonigaba | Student, Grade 11 | (Level 1) Salutatorian

Posted September 28, 2012 at 10:33 AM (Answer #3)

dislike -1 like

Slope m= y2-y1/x2-x1

-1-0/1-0

-1/1

=-1

equatio of line: y=mx+c

-1=-1+c

c=0

y=-x

this the equation.


Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes