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Question:

Suppose that the points (h,k), (1,2) and (-3,4) lie on the line L1. If a line L2 passing through the points (h,k) and (4,3) is perpendicular to L1, then k equals:

3

-1/7

13

0

Solution:

Correct option is C. 1/3
equation of L1 is y = -1/2x + 5/2 (1)
equation of L2 is y = 2x - 5.. (2)
by (1) and (2) x=3 y=1 ⇒ h=3, k=1
k/h = 1/3