Answer:
see explanation
Step-by-step explanation:
If (x - a ) is a factor of f(x) , then f(a) = 0
given
f(x) = x³ - x² - 4x + 4
If (x - 1 ) is a factor then f(1) = 0
f(1) = 1³ - 1² - 4(1) + 4 = 1 - 1 - 4 + 4 = 0
Then (x - 1 ) is a factor of the polynomial