Question

If 

then \( y \) is equal to: 
 

• A. 1
• B. 3
• C. 2
• D. 4

Hint:

Always look for the simplest equation first (like \( x=3 \)) to find one variable, then use it to solve the more complex equations.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Equality of matrices states that two matrices are equal if they have the same order and their corresponding elements are equal.
Step 2: Detailed Explanation: We compare elements at each position \( (i, j) \).
Comparing element \( a_{22} \):
\[ x = 3 \]
Comparing element \( a_{11} \):
\[ x - 2y = -5 \]
Now, substitute the value of \( x = 3 \) into the second equation:
\[ 3 - 2y = -5 \]
Isolate the term with \( y \):
\[ -2y = -5 - 3 \] \[ -2y = -8 \]
Divide by \( -2 \):
\[ y = \frac{-8}{-2} = 4 \]
Step 3: Final Answer:
The value of \( y \) is 4.