What is the slope of the line described by the equation below? y - 5= -3(x - 17)

First distribute -3 to both x and -17
-3(x) = -3x
-3(-17) = 51

y - 5 = -3x + 51

isolate the y, add 5 to both sides

y - 5 (+5) = -3x + 51 (+5)

add all numbers with same variables together

y = -3x + 51 + 5
y = -3x + 56

inside the slope intercept form:

y = y
m = slope
x = x
b = intercept.

y = mx + b (using this equation, we can see that -3 = m)

-3 is slope, and is your answer 

hope this helps