Answer:
c = 5
Explanation:
The slope is the change in y over the change in x. Or as I memorized RISE OVER RUN. Also in physics, you can write ∆y/∆x. Delta (∆) just means change.
Using this equation we have
The slope = m = 3 = ∆y/∆x
m = (-1 - c)/(-8 - -6) = (-1 - c)/(-8+6) = (-1 - c)/(-2) = 3
Now multiply both sides of the equation by -2 and you get
(-1 - c) = 3•(-2) = -6
Almost there!
Now we have the equation
-1 - c = -6
Add one to both sides and you get
-1+1-c = -6 +1
Simplified that equals
-c = -5
Then to get our answer we have to go from negative to positive.
Multiplying both sides by -1 we get
-1 • -c = -1 • -5
c = 5
Now CHECK!
Plug c into the equation ∆y/∆x and you get a slope of 3 which proves the answer is right.