To solve this problem, first, we have to find the slope of the line that has an x-intercept of 3 and a y-intercept of 6. The intercepts can be written as (3,0) and (0,6). Let's use the slope formula

Where,

Let's use these values to find the slope.

The slope of the line that has the given intercepts is m = -2.
Now, we have to find the perpendicular slope of m = -2 using the following rule

Let's replace the slope we found and find the other one.

The slope of the perpendicular line is 1/2.
Once we have the slope of the new perpendicular line, we use the point-slope formula

Where,

Let's use these values above to find the equation of the new perpendicular line.

Therefore, the equation of the new perpendicular line that passes through (-6,4) is

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