Answer: (x-4)
I just took the test and that's the answer. I can't explain it though.
Answer: (x - 4)
Step-by-step explanation:
Go through all the available options using synthetic division to find which one is a factor.
I'm not going to go through each one because that will take a long time, but I will show you why (x - 4) is the correct answer.
I will be using this symbol to represent division: |
1. Write out the equation:
-4| 3x^3 + 8x^2 - 87x + 28
2. Change the sign in front of the four (it becomes positive) and bring down all the polynomial's base numbers:
4| 3 8 -87 28
3. Bring down the first base number (3) to start. Multiply 4 by each of the resulting numbers and add the resulting numbers to the base numbers:
4 x 3 = 12, 8 + 12 = 20, 4 x 20 = 80, -87 + 80 = -7, 4 x -7 = -28, 28 + (-28) = 0
4| 3 8 -87 28
12 80 -28
---------------------
3 20 -7 0 < remainder
4. You have your answer!
The answer is (x - 4) because the remainder is 0.
