How to find slope intercept form for perpendicular lines

To find the slope intercept form of a line perpendicular to a given equation, the first thing you need to do is to find the slope of the perpendicular line. Because lines perpendicular to one another are always have a slope that is the negative reciprocal of them, the slope of the line perpendicular to y=x would be -1 (since the slope of y=x is 1). Then, since the perpendicular line passes through the point (5, -3), you would plug in the values of the x and y into the equation
y=-1x+b to get -3=-1(5)+b.

When you simplify, solve for b to get b=2. Now that you have your slope (m=-1) and your y-intercept (b=2), you can conclude that your perpendicular equation would be y=-x+2.