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MP Board · Class 10 · Mathematics · Pair of Linear Equations in Two VariablesFor what value of $k$ does the pair of linear equations $x + 2y - 3 = 0$ and $5x + ky + 7 = 0$ represent parallel lines?

Step-by-Step Solution

For parallel lines (no solution), the algebraic condition is:\n$$\frac{a_1}{a_2} = \frac{b_1}{b_2} \neq \frac{c_1}{c_2}$$\n\nComparing given equations with standard form:\n- $a_1 = 1, b_1 = 2, c_1 = -3$\n- $a_2 = 5, b_2 = k, c_2 = 7$\n\nNow, set:\n$$\frac{1}{5} = \frac{2}{k}$$\n\nCross-multiplying gives:\n$$k = 10$$\n\nAlso, $\frac{2}{10} \neq \frac{-3}{7}$, which holds true. Thus, $k = 10$.

Detailed Options Breakdown
Option : $k = 5$

Incorrect choice. This distractor represents a common misunderstanding of the core principles of Pair of Linear Equations in Two Variables.

Option 1: $k = 10$ (Correct Answer)

Correct choice. Refer to the step-by-step verified solution guidelines above for details.

Option 2: $k = -10$

Incorrect choice. This distractor represents a common misunderstanding of the core principles of Pair of Linear Equations in Two Variables.

Option 3: $k = 2$

Incorrect choice. This distractor represents a common misunderstanding of the core principles of Pair of Linear Equations in Two Variables.

💡 Study Guide: This question tests core syllabus concepts from Pair of Linear Equations in Two Variables. For formulas, key summaries, and mock exam reference guides, read the full Pair of Linear Equations in Two Variables Revision Notes.
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