Answer:
Step-by-step explanation:
The remainder theorem says that when you put the integer part of the binomial for the value of x in f(x), you can solve for the remainder.
f(x) = x^3 - 4x + k is divided by (x - 5) means that 5 is put into f(x)
f(5) = x^3 - 4x + k now put 5 into x on the right
f(5) = 5^3 - 4(5) + k
f(5) = 125 - 20 + k = 91
f(5) = 105 + k = 91
105 + k = 91 Subtract 105 from both sides
k = 91 - 105
k = -14
