Find the value of ‘P’ for which lines (P - 1)x + y - 5 = 0 and (2 - P)x - 3y + 2 = 0 are parallel?
Find the value of ‘P’ for which lines (P - 1)x + y - 5 = 0 and (2 - P)x - 3y + 2 = 0 are parallel? Correct Answer 1 / 2
Given:
L1; (P - 1)x + y - 5 = 0
L2; (2 - P)x - 3y + 2 = 0
L1 / / L2
Formula used:
If two lines are parallel, then, the slope of both lines will be same.
Calculation:
L1; (P - 1)x + y - 5 = 0
⇒ y = - (P - 1)x + 5
⇒ y = (1 - P)x + 5
We know y = mx + c, where m = slope, comparing the above equation, we get:
∴ Slope = (1 - P) ----(1)
L2; (2- P)x - 3y + 2 = 0
⇒ 3y = (2 - P)x + 2
⇒ y = (2 - P)x / 3 + 2 / 3
We know y = mx + c, where m = slope, comparing the above equation, we get:
∴ Slope = (2 - P) / 3 ----(2)
Now, (1 - P) = (2 - P) / 3
⇒ (3 - 3P) = (2 - P)
⇒ (3P - P) = (3 - 2)
⇒ 2P = 1
⇒ P = 1 / 2
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Feb 20, 2025