An Important Question of class 10 Based on Equation of a Straight Line Chapter of M.L Aggarwal for ICSE BOARD.

Here two parallel lines are given so you have find the value of p asked in question.

This is the Question Number 02, Exercise 12.2 of M.L Aggarwal.

Deepak BoraNewbie

# If 6x + 5y – 7 = 0 and 2px + 5y + 1 = 0 are parallel lines, find the value of p.

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For two lines to be parallel, their slopes must be same.

Given line equations,

6x + 5y – 7 = 0 and 2px + 5y + 1 = 0

In equation 6x + 5y – 7 = 0,

5y = -6x + 7

y = (-6/5) x + 7/5

So, the slope of the line (m

_{1}) = -6/5Again, in equation 2px + 5y + 1 = 0

5y = -2px – 1

y = (-2p/5) x – 1/5

So, the slope of the line (m

_{2}) = -2p/5For these two lines to be parallel

m

_{1}= m_{2}-6/5 = -2p/5

p = (-6/5) x (-5/2)

Thus, p = 3