Answer:
x = 2
Step-by-step explanation:
h(x) = f(x) + g(x) = x³ + 2x² + 1 - x³ - x² - 4x + 4 ← collect like terms, thus
h(x) = f(x) + g(x) = x² - 4x + 5
Given
h(x) = 1, then
x² - 4x + 5 = 1 ( subtract 1 from both sides )
x² - 4x + 4 = 0 ← in standard form
(x - 2)² = 0 ← in factored form ( perfect square ), thus
x - 2 = 0 ⇒ x = 2