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27 votes
27 votes
Write the equation of the line that passes through the point (4,−1) that is parallel to the line 2x−3y=9

User Umair Khan Jadoon
by
2.8k points

2 Answers

12 votes
12 votes

First we find the slope of the line 2x−3y+8=0 by placing it into slope intercept form:

2x−3y+8=0

⇒−3y=−2x−8

⇒3y=2x+8

⇒y=

3

2

x+

3

8

Therefore, the slope of the line is m=

3

2

.

Now since the equation of the line with slope m passing through a point (x

1

,y

1

) is

y−y

1

=m(x−x

1

)

Here the point is (2,3) and slope is m=

3

2

, therefore, the equation of the line is:

y−3=

3

2

(x−2)

⇒3(y−3)=2(x−2)

⇒3y−9=2x−4

⇒2x−3y=−9+4

⇒2x−3y=−5

Hence, the equation of the line is 2x−3y=−5.

User VaMoose
by
3.0k points
17 votes
17 votes

Answer:

y=2/3x-11/3

Explanation:

Hi there!

We are given the equation 2x-3y=9 and we want to write an equation that is parallel to it and that passes through (4,-1)

Parallel lines have the same slopes

So we need to first find the slope of 2x-3y=9

We can do this by converting the equation of the line from standard form (ax+by=c where a, b, and c are integers) to slope-intercept form (y=mx+b, where m is the slope and b is the y intercept)

To do this, we need to isolate y on one side

2x-3y=9

subtract 2x from both sides

-3y=-2x+9

divide both sides by -3

y=2/3x-3

as 2/3 is in the place where m is, 2/3 is the slope of the line

It's also the slope of the line parallel to it that passes through (4,-1).

Here's the equation of that line so far:

y=2/3x+b

now we need to find b

as the line will pass through the point (4,-1), we can 4 as x and -1 as y in order to solve for b

-1=2/3(4)+b

multiply

-1=8/3+b

subtract 8/3 to both sides

-11/3=b

Substitute -11/3 as b into the equation

y=2/3x-11/3

There's the equation

Hope this helps!

User Cajwine
by
3.2k points