Question

x^2-8xy+15y^2

Answer 1

Factor again?

Answer 2

The first term is x^2 which is the square of x
The last term is 15y^2. 15 is not a perfect square, so this is not the square of a sum.
For this type of factoring, you set up two sets of parentheses.

Answer 3

x^2-8xy+15y^2
( )( )
Since x^2 = x*x, place x in each parentheses on the left side:
(x )(x )
Since the last term has y^2, and y^2 = y*y, you need y on the right sides inside the parentheses
(x y)(x y)
Now you need two numbers that multiply to 15, and add up to -8
They are -3 and -5
Now you place them in the parentheses, on the right sides.
(x - 3y)(x - 5y)
To check, multiply it out with FOIL to make sure you get x^2 - 8xy + 15y^2

Answer 4

Ohhh my gosh! You are the best! Thank you so much, you actually explained it!!!

Answer 5

So if i were to have x^2+2x-15 i would first put them in the parentheses like (x )(x )?

Answer 6

Yes.
First, notice that while x^2 is the square of x, -15 is certainly not a perfect square. Therfore, this is not the square of a sum.
So, you try (x )(x )
Now look for two numbers that multiply to -15 and add up to 2