Factorise 3(2x + 3y)^2 - 8x - 12y
First, we FOIL it.
FOIL: First, Outside, Inside, and Last
(2x + 3y)(2x + 3y)
First: 2x*2x = 4x^2
Outside: 2x*3y = 6xy
Inside: 3y*2x = 6xy
Last: 3y*3y = 9y^2
Before, we move on, we have to combine any like terms.
6xy + 6xy = 12xy
Then, when we've finished FOILing it, we place a pair of parentheses around these.
3 (9y^2 + 4x^2 + 12xy) -8x - 12y
Now, we can distribute the 3.
3 * 9y^2 = 27y^2
3 * 4x^2 = 12x^2
3 * 12xy = 36xy
Lastly, we combine any like terms if there are any.
Expression: 27y^2 + 12^2 + 36xy - 8x - 12y
None of these all have a greatest common factor for the whole set.
So, therefore, the factorised form of 3(2x + 3y)^2 - 8x - 12y is:
27y^2 + 12x^2 + 36xy - 8x - 12y