Which of the following will be the equation of a straight line parallel to the y-axis at a distance of 9 units to the left?

Options

A. x = - 9
B. x = 9
C. y = 9
D. y = - 9 2

Answer

To find the equation of a straight line that is parallel to the y-axis and located 9 units to the left, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Position of the Line**:
- A line that is parallel to the y-axis will have a constant x-coordinate. This means that for any point on this line, the x-coordinate remains the same while the y-coordinate can vary.

2. **Identifying the Distance**:
- The problem states that the line is 9 units to the left of the y-axis. The y-axis is represented by the line where x = 0. Therefore, moving 9 units to the left means we are moving towards the negative x-direction.

3. **Determining the x-coordinate**:
- Since we are moving 9 units to the left from the origin (0,0), the x-coordinate of the line will be -9.

4. **Writing the Equation**:
- The equation of a line that is parallel to the y-axis and has a constant x-coordinate of -9 is given by:
\[ x = -9 \]

### Final Answer:
The equation of the straight line parallel to the y-axis at a distance of 9 units to the left is:
\[ x = -9 \]