Please guide me the best way for solving the question of class 9th math of Polynomials chapter of exercise 2.5 of math of question no.8(3) What is the best way for solving this question, please guide me Factorise each of the following:(iii) 27–125a3–135a +225a2
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The expression, 27–125a3–135a +225a2 can be written as 33–(5a)3–3(3)2(5a)+3(3)(5a)2
27–125a3–135a+225a2 =
33–(5a)3–3(3)2(5a)+3(3)(5a)2
= (3–5a)3
= (3–5a)(3–5a)(3–5a)
Here, the identity, (x–y)3 = x3–y3-3xy(x–y) is used.