Answer:

Explanation:
- We know that when two lines are perpendicular, their slopes are negative reciprocals. The following formula shows this fact:
, where
- m2 is the slope of the line we're trying to find
- m1 is the slope of the line we're given
Step 1: Currently 3x + y = -5 is in standard form, but we can isolate y to convert the line to slope-intercept form (y = mx + b) to find the slope, m:
3x + y = -5
y = -3x + 5
Thus, the slope of the first line is -3. We plug in -3 for m1 in the perpendicular slope formula to find m2 or the slope of the line we're still trying to find:
m2 = -1 / -3
m2 = 1/3
Step 2: Now that we know the slope of the other line, we plug in the point (3, -7) for x and y and 1/3 for m in the slope-intercept form. Then, we must solve for b to find the y-intercept of the other line:
-7 = 1/3(3) + b
-7 = 1 + b
-8 = b
Thus, the equation of the line that is perpendicular to 3x + y = -5 and passes through (3, -7) = y = 1/3x - 8