Given two straight lines x 3y 2 and 3x ky 4 0 if the two lines are parallel the value of k is

Solution:

Given, the linear pair of equations are

3x + 2ky = 2

2x + 5y + 1 = 0

We have to find the value of k.

We know that,

For a pair of linear equations in two variables be a₁x + b₁y + c₁ = 0 and a₂x + b₂y + c₂ = 0,

If \(\frac{a_{1}}{a_{2}}=\frac{b_{1}}{b_{2}}\neq \frac{c_{1}}{c_{2}}\), then the graph will be a pair of parallel lines.

Here, a₁ = 3, b₁ = 2k, c₁ = -2

a₂ = 2, b₂ = 5, c₂ = 1

So, a₁/a₂ = 3/2

b₁/b₂ = 2k/5

c₁/c₂ = -2/1 = -2

By using the above result,

\(\frac{3}{2}=\frac{2k}{5}\)

On cross multiplication,

3(5) = 2(2k)

15 = 4k

So, k = 15/4

Therefore, the value of k is 15/4.

✦ Try This: If the lines given by 2x + 3ky = 2 and 3x + 5y + 1 = 0 are parallel, then the value of k is

Given, the linear pair of equations are

2x + 3ky = 2

3x + 5y + 1 = 0

We are required to find the value of k.

Here, a₁ = 2, b₁ = 3k, c₁ = -2

a₂ = 3, b₂ = 5, c₂ = 1

So, a₁/a₂ = 2/3

b₁/b₂ = 3k/5

c₁/c₂ = -2/1 = -2

By using the above result,

\(\frac{2}{3}=\frac{3k}{5}\)

On cross multiplication,

2(5) = 3(3k)

10 = 9k

So, k = 10/9

Therefore, the value of k is 10/9

☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 3

NCERT Exemplar Class 10 Maths Exercise 3.1 Problem 7

Summary:

If the lines given by 3x + 2ky = 2 and 2x + 5y + 1 = 0 are parallel, then the value of k is 15/4

☛ Related Questions:

If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

1 Expert Answer

Given two straight lines x 3y 2 and 3x ky 4 0 if the two lines are parallel the value of k is

Ben K. answered • 05/16/16

JHU Grad specializing in Math and Science

First, put each equation into slope-intercept form. This will help because we will then have a slope for each equation. As a reminder the slope-intercept form looks like:

The coefficient 'm' is the slope of the line

The first one looks like...

subtract the 1 and the 3x from each side to get

The slope of this line is -3/4. The next equation looks like...

ky = -4x - 3 after doing similar operations.

We don't care about the -3/k term at the far right because that is the intercept. We only care about the slope term, because the problem wants us to find k such that the the lines are parallel. The thing that makes any two lines parallel is that their slopes have the same value. Thus, we want (-4/k) to be equal to (-3/4).

First, those pesky negatives cancel out.

Now you can cross-multiply to get

Now divide by 3 so that you isolate 'k'

Hey! We have now found 'k' such that the two lines are parallel.

I hope this helps! Please let me know if you have any questions.

Kiva C.

asked • 02/11/21

Find the value of k such that the following two lines are parallel.

2​x​ + ​y​ =5 ; ​x​ – k​y​ = 7

4 Answers By Expert Tutors

Put 2​x​ + ​y​ =5 into the slope intercept form y = 5 - 2x. The slope is -2. If the lines are parallel, the slopes must be equal. Put the equation x​ – k​y​ = 7 into the slope intercept form y = x/k -7/k.

For the slopes to be equal, 1/k = -2 or k = -1/2, so the equation becomes y = -2x +14

Given two straight lines x 3y 2 and 3x ky 4 0 if the two lines are parallel the value of k is

Bradford T. answered • 02/11/21

Retired Engineer / Upper level math instructor

Rewrite both equations in y = mx+b form

y = -2x +5

ky = x-7 --> y = (x -7)/k --> y = x/k - 7/k

To make the lines parallel, both lines need to have the same slope which is -2.

1/k = -2 --> k = -1/2

Niko M. answered • 02/11/21

Spreading mathematics throughout the land

The slopes of both lines must be equal in order to be parallel.

First line can be y = -2x + 5, so slope is -2

Second line can be y = (1/k)x - 7/k, so slope is 1/k

Since slopes must be equal, then -2 = 1/k , or -2k = 1, or k = -1/2

Given two straight lines x 3y 2 and 3x ky 4 0 if the two lines are parallel the value of k is

Jarom L. answered • 02/11/21

Passionate Tutor Specializing in Middle School through College Math