Answer:
4
Step-by-step explanation:
If f(x)= 108-kx, then all you have to do is plug in the given value of x which is -4, then equal it to the given value of 124.
[tex]108 - kx = 124\\108 - k(-4) = 124\\\\108 + 4k = 124\\\\4k = 124 - 108\\\\k = 16/4\\\\k = 4[/tex]
