Questions: Question 11
Choose the correct answer. Factor (f(x)) into linear factors. [ f(x)=x^3-3 x^2-49 x+147 ] (A) (f(x)=(x-7)(x-3)(x+3)) (B) (f(x)=(x-7)(x+3)(x+7)) (C) (f(x)=x(x-7)(x-3)) (D) (f(x)=(x-7)(x-3)(x+7))
Transcript text: Question 11
Choose the correct answer.
Factor $f(x)$ into linear factors.
\[
f(x)=x^{3}-3 x^{2}-49 x+147
\]
(A) $f(x)=(x-7)(x-3)(x+3)$
(B) $f(x)=(x-7)(x+3)(x+7)$
(C) $f(x)=x(x-7)(x-3)$
(D) $f(x)=(x-7)(x-3)(x+7)$
Solution
Solution Steps
To factor the polynomial \( f(x) = x^3 - 3x^2 - 49x + 147 \) into linear factors, we can use the Rational Root Theorem to find potential rational roots. Once we find a root, we can use polynomial division to factor out the corresponding linear factor and repeat the process for the resulting polynomial.
Step 1: Identify the Polynomial
We start with the polynomial given by
\[
f(x) = x^3 - 3x^2 - 49x + 147.
\]
Step 2: Find the Roots
Using the Rational Root Theorem, we find the roots of the polynomial. The roots are
\[
x = -7, \quad x = 3, \quad x = 7.
\]
Step 3: Factor the Polynomial
Using the roots, we can express the polynomial in its factored form as
\[
f(x) = (x - 7)(x - 3)(x + 7).
\]
Final Answer
The correct factorization of the polynomial is
\[
\boxed{(x - 7)(x - 3)(x + 7)}.
\]