y=kx+b
for (7,-8): -8=7k+b. (function 1)
for (-4,6): 6=-4k+b (function 2)
Use function 2 - function 1
we get: 14=-11k
k=-14/11------>slope is -14/11
Now we know that first two options are wrong since they have the wrong slope for the function.
Plus -14/11 back to function 1/ or 2. Both are correct and can give you the answer. In this case I would plug it back to function 2.
6=14*4/11+b
b=66/11-56/11
b=10/11
We get y=-14/11x+10/11
subtract both side by 6.
y-6=-14/11x+10/11-66/11
y-6=-14/11x-56/11
y-6=-14/11(x+4)
So C is correct
