Question

Factor of a Polynomial
21AB - 14AX + 15BY - 10XY

Please show me steps on how to solve this! Thanks!

Answer 1

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)

if it was written like this i could follow you.