Answer:
c=3
Explanation:
We have 2 points, we can find the slope using
m = (y2-y1)/(x2-x1)
Substituting into this equation
-1/4 = (4-5)/(7-c)
-1/4 = -1/(7-c)
Multiply both sides by -1
1/4 = 1/(7-c)
The denominators have to be the same
4 = 7-c
Subtract 7 from each side
4-7 = 7-7-c
-3 = -c
Multiply by -1
3 =c