Question

Complete the following activity and find the value of x:

5x + 3y = 9     ...(I)
2x − 3y = 12     ...(II)

Hint:

When two linear equations have opposite coefficients for one variable, adding or subtracting them eliminates that variable — making it easier to solve for the other one.

Answer 1

Step 1: Write down the two equations.
\[ \text{(I)} \; 5x + 3y = 9 \] \[ \text{(II)} \; 2x - 3y = 12 \] Step 2: Add equations (I) and (II).
\[ (5x + 3y) + (2x - 3y) = 9 + 12 \] Step 3: Simplify.
\[ 7x = 21 \] Step 4: Solve for \(x\).
\[ x = \frac{21}{7} = 3 \] Step 5: Conclusion.
Hence, the value of \(x\) is 3.
Final Answer: \[ \boxed{x = 3} \]