Answer:
k = -4
Step-by-step explanation:
The remainder theorem tells you that the remainder from division f(x)/(x -k) is f(k). You want the value of k such that ...
f(k) = -15
Looking on the given graph, you find that k must be -4. That is, ...
f(-4) = -15
k = -4
_____
The divisor with k=-4 is (x -(-4)) = (x +4). The second attachment shows the division of f(x) by (x+4). The remainder is shown on the bottom line.
