Find the missing side length, k.

Step-by-step explanation:

a & c are given

to find k, let us use k as b

In summary, m = -1/6 and b = 5

Step-by-step explanation:

As we move from A(–6, 6) to B(12, 3), x increases by 18 and y decreases by 3.  Thus, the slope of Line AB is m = rise / run = -3 / 18, or m = -1/6.

Let's make use of the slope-intercept formula to find the value of b:

y = mx + b  becomes 3 = (-1/6)(12) + b, or

                                   3 = -2 + b

Then b must be 5.

In summary, m = -1/6 and b = 5, and the equation of Line AB is y = (-1/6)x + 5.