If x=1, y=1 is solution of equation 9ax + 12ay =63 then the value of a is

Options

A. 3
B. 0
C. `-3`
D. 4

Answer

To find the value of \( a \) given that \( (x, y) = (1, 1) \) is a solution of the equation \( 9ax + 12ay = 63 \), we will follow these steps:

### Step 1: Substitute the values of \( x \) and \( y \) into the equation.
We know that \( x = 1 \) and \( y = 1 \). So we substitute these values into the equation:

\[ 9a(1) + 12a(1) = 63 \]

### Step 2: Simplify the equation.
This simplifies to:

\[ 9a + 12a = 63 \]

### Step 3: Combine like terms.
Now, we combine the terms on the left side:

\[ (9a + 12a) = 21a \]

So the equation now is:

\[ 21a = 63 \]

### Step 4: Solve for \( a \).
To find \( a \), we divide both sides of the equation by 21:

\[ a = \frac{63}{21} \]

### Step 5: Simplify the fraction.
Now we simplify \( \frac{63}{21} \):

\[ a = 3 \]

Thus, the value of \( a \) is \( 3 \).

### Final Answer:
The value of \( a \) is \( 3 \).

---