Final answer:
To factor the polynomial 7a³-14a²-21a, you can factor out the common factor 7a. Then, factor the trinomial a² - 2a - 3. The factored form of the polynomial is 7a(a - 3)(a + 1).
Step-by-step explanation:
To factor the polynomial 7a³-14a²-21a, we first look for a common factor among the terms. In this case, we can factor out 7a. Factoring out the common factor, we get:
7a(a² - 2a - 3)
Next, we factor the trinomial a² - 2a - 3 using the quadratic formula or by factoring techniques:
7a(a - 3)(a + 1)
So the polynomial 7a³-14a²-21a is factored into 7a(a - 3)(a + 1).