Answer:
f(x) = (x + 7)^2 - 41
Step-by-step explanation:
f(x) = x^2 + 14x + 8
We take half of the coefficient of the x-term and square it.
Half of 14 is 7. 7 squared is 49. We add 49 to complete the square, but we then must subtract it at the end to not change the value of the function.
f(x) = x^2 + 14x + 49 + 8 - 49
f(x) = (x + 7)^2 - 41
