Factorise:
7(x−2y)2−25(x−2y)+12
Given 7(x−2y)2−25(x−2y)+12Put x−2y=vEquation becomes 7v2−25v+12By splitting the midddle term,we get⇒7v2−21v−4v+12⇒7v(v−3)−4(v−3)⇒(7v−4)(v−3)Put the value back⇒(7(x−2y)−4)(x−2y−3)⇒(7x−14y−4)(x−2y−3)
∴ 7(x−2y)2−25(x−2y)+12 = (7x-14y-4)(x-2y -3)