SAMathematics

CBSE · Class 10 · Mathematics · Pair of Linear Equations in Two VariablesSolve the pair of linear equations $2x + 3y = 11$ and $2x - 4y = -24$ by substitution method. Hence, find the value of '$m$' for which $y = mx + 3$.

Step-by-Step Solution

Given equations are:

  1. $2x + 3y = 11$
  2. $2x - 4y = -24$

Step 1: From equation (2), express $x$ in terms of $y$: $$2x = 4y - 24$$ $$x = 2y - 12 \quad \text{--- (3)}$$

Step 2: Substitute the value of $x$ from (3) into equation (1): $$2(2y - 12) + 3y = 11$$ $$4y - 24 + 3y = 11$$ $$7y - 24 = 11$$ $$7y = 35$$ $$y = 5$$

Step 3: Substitute $y = 5$ in equation (3): $$x = 2(5) - 12$$ $$x = 10 - 12 = -2$$ \nSo, the solution is $x = -2$ and $y = 5$.

Step 4: Find the value of $m$ using $y = mx + 3$: $$5 = m(-2) + 3$$ $$5 - 3 = -2m$$ $$2 = -2m$$ $$m = -1$$

Final Answer: $x = -2$, $y = 5$, and $m = -1$.

💡 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.
← All Chapter QuestionsMathematics Chapters