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
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. Find the value of k such that the following two lines are parallel. 2x + y =5 ; x – ky = 7 4 Answers By Expert Tutors Put 2x + 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 – ky = 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
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
Jarom L. answered • 02/11/21 Passionate Tutor Specializing in Middle School through College Math
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