Answer:

Step-by-step explanation:
We have to write an equation of a line which  passes through the given point (-9,2) and is perpendicular to the given straight line y = 3x - 12 ........... (1)
Now, equation (1) is in the slope-intercept form and the slope of the line is 3.
Let, m is the slope of the required line.
So, 3m = -1
{Since, the product of the slopes of two perpendicular straight lines is -1}
⇒  
Therefore, the equation of the required line in slope intercept form is  
 {Where c is a constant}
 {Where c is a constant}
Now, this above equation passes through the point (-9,2) point.
So,  
⇒ 2 = 3 + c
⇒ c = - 1  
Therefore, the equation of the required straight line is  (Answer)
 (Answer)