Tamil Nadu Board of Secondary EducationSSLC (English Medium) Class 9th

# The value of k for which the pair of linear equations 4x + 6y – 1 = 0 and 2x + ky – 7 = 0 represents parallel lines is - Mathematics

MCQ

The value of k for which the pair of linear equations 4x + 6y – 1 = 0 and 2x + ky – 7 = 0 represents parallel lines is

• k = 3

• k = 2

• k = 4

• k = − 3

#### Solution

k = 3

Explanation;

Hint:

Slope of 4x + 6y – 1 = 0

6y = – 4x + 1

⇒ y = (-4)/6x + 1/6

Slope = (-4)/6 = (-2)/3

Slope of 2x + ky – 7 = 0

ky = – 2x + 7

y = (-2)/"k"x + 7/"k"

Slope of a line = (-2)/"k"

Since the lines are parallel

(-2)/3 = (-2)/"k"

– 2k = – 6

k = 6/2

= 3

Concept: Simultaneous Linear Equations
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#### APPEARS IN

Samacheer Kalvi Mathematics Class 9th Tamil Nadu State Board
Chapter 3 Algebra
Exercise 3.15 | Q 24 | Page 135