12x2 – 17xy + 6y2
Here, coefficient of x2 = 12, coefficient of x = -17 and constant term = 6y2
We shall now split up the coefficient of middle term i.e., -17y into two parts whose sum is -17y and product is 12 x 6y2 = 72y2
Clearly,
-9y – 8y = -17y and
(-9y) (-8y) = 72y2
So, we replace middle term -17xy = - 9xy – 8xy
Thus, we have
12x2 -17xy+ 6y2 = 12x2 - 9xy - 8xy + 6y2
= 3x (4x – 3y) – 2y (4x – 3y)
= (3x – 2y) (4x – 3y)