ANSWER
[tex]\begin{gathered} x=1+4i \\ x=1-4i \end{gathered}[/tex]EXPLANATION
Given:
[tex]\begin{gathered} f(x)=x^3-6x^2+25x-68 \\ \end{gathered}[/tex]Also,
One of the zeros: x = 4
Desired Outcome:
List the remaining zeros using radicals and i.
Simplify the polynomial using x - 4 = 0
Determine the remaining polynomials by simplifying x^2 - 2x + 17 = 0 using the quadratic formula
[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]where:
a = 1,
b = -2
c = 17
Substitute the values
[tex]\begin{gathered} x=\frac{-(-2)\pm\sqrt{(-2)^2-4(1)(17)}}{2(1)} \\ x=\frac{2\pm\sqrt{4-68}}{2} \\ x=\frac{2\pm\sqrt{-64}}{2} \\ x=\frac{2\pm\sqrt{64\times-1}}{2} \\ x=\frac{2\pm(\sqrt{64}\times\sqrt{-1})}{2} \\ x=\frac{2\pm8\sqrt{-1}}{2} \\ x=1\pm4\sqrt{-1} \\ \text{ Recall: }\sqrt{-1}\text{ = }i \\ x=1\pm4i \\ x=1+4i\text{ }or \\ x=1-4i \end{gathered}[/tex]