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AP EAMCET · Maths · Pair of Lines

If \(a x^2+2 h x y-2 a y^2+3 x+15 y-9=0\) represents a pair of lines intersecting at \((1,1)\), then ah \(=\)

  1. A 14
  2. B -15
  3. C -7
  4. D 9
Verified Solution

Answer & Solution

Correct Answer

(C) -7

Step-by-step Solution

Detailed explanation

\(a+h+3/2=0 \implies a+h=-3/2\) \(h-2a+15/2=0 \implies -2a+h=-15/2\) \(3a = -3/2 - (-15/2) = 12/2 = 6 \implies a=2\) \(2+h=-3/2 \implies h=-7/2\) \(ah = (2)(-7/2) = -7\)