Find the value of k for which the pair of equations x + 2y - 3 = 0 and 5x + ky + 7 = 0 represents parallel lines
Correct: B
For parallel lines, the coefficients must be proportional: 1/5 = 2/k ≠ -3/7. Solving 1/5 = 2/k ⇒ k = 10. However, 1/5 ≠ -3/7, which is true. Thus, k = 10 satisfies the condition.