The graphs of the linear equations 4x - 2y = 10 and 4x + ky = 2 intersect at a point (a, 4). The value of k is equal to:
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Correct answer: D
Explanation
The correct answer is option 4 i.e. -4.
(a, 4) is the intersection point of the given lines.
It implies that this point satisfies both the lines.
⇒ 4 × a - 2 × 4 = 10
⇒ 4a - 8 = 10
⇒ 4a = 18
⇒ a = 4.5
4x + ky = 2
⇒ 4 × a + k × 4 = 2
⇒ 4 × 4.5 + 4k = 2
⇒ 4k = -16
k = -4