Question

Factor of a polynomial
2x^2 - x - 55 Please show me the steps on how to solve. thanks!

Answer 1

2x^2 - x - 55
Step 1: Write two sets of parentheses
( )( )
Step 2: What does 2x^2 factor into? 2x and x
Write that on the left side of each set parentheses
(2x )(x )
Step 3: How can you factor -55? There are several choices:
-55, 1
-1, 55
-11, 5
-5, 11
These are the numbers that will go in the right sides of the parentheses, but how do you choose the right ones?
You need to try guess, and then check the guess to see if it works.
Start with -11, 5
(2x - 11)(x + 5)
Do OI of FOIL and see if you get the original middle term, -x
2x(5) + (-11)x = 10x - 11x = -x (good guess)
Therefore final answer is
(2x - 11)(x + 5)

Answer 2

Aww thanks man! This is how i need it to learn xD