This equation is n the general form of the equation of a line, right? In order to rewrite it in the slope intercept form, we have to manipulate it. Let's go:
![-x\text{ -7y = 14 is given. We want to rewrite it as y = mx +b, which is the slope intercept equation. So, -7y = x +14}]()
Multiplying both sides by (-1), we'll have 7y = -x - 14
Now we divide both sides by 7,
y = -1/7x - 2. So, m, the slope of this line is -1/7, ok?
Two parallel lines have the same slope, thus, the slope of a parallel line will also be -1/7.
Two perpendicular lines have reciprocal negative slopes, so -1/7 = +7.