Line K has a slope of 3. Line J is perpendicular to like K and passes through the point (3,8). Type the equation of the line in y=Mx+b

I'm assuming you are finding the equation of the line of Line J

Slope-intercept form:  y = mx + b

[m is the slope, b is the y-intercept or the y value when x = 0 --> (0, y) or the point where the line crosses through the y-axis]

For lines to be perpendicular, the slopes have to be negative reciprocals of each other. (basically changing the sign (+/-) and flipping the fraction/switching the numerator and the denominator)

For example:

slope = 2 or  

Perpendicular line's slope =    [changed sign from + to -, and flipped the fraction]

slope =

Perpendicular line's slope =   [changed sign from - to +, and flipped the fraction]

Since you know the slope is 3, the perpendicular line's slope is .  Plug this into the equation

y = mx + b

   To find b, plug in the point (3, 8)

8 = -1 + b    Add 1 on both sides to get "b" by itself

8 + 1 = -1 + 1 + b

9 = b

b.-4 units

all you   do is count how many times you move