To solve the equation \( ax - 12 = 9 \), we first isolate \( ax \):
-
Add 12 to both sides: \[ ax = 9 + 12 \] \[ ax = 21 \]
-
Now, divide both sides by \( a \) to solve for \( x \): \[ x = \frac{21}{a} \]
So the solution is \( x = \frac{21}{a} \).
The correct answer matches with options A and B:
A. x = 21/a
B. x = 21/a
Thus, both A and B are correct.