What is the best way for solving the problem of question from class 9th of ncert of Polynomials chapter of exercise 2.5 of question no.1(3) give me the best solution of this question in easy way Use suitable identities to find the following products:(iii) (3x+4)(3x–5)
AnilSinghBoraGuru
Use suitable identities to find the following products:(iii) (3x+4)(3x–5) Q.1(3)
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Using the identity, (x+a)(x+b) = x 2+(a+b)x+ab
[Here, x = 3x, a = 4 and b = −5]
We get,
(3x+4)(3x−5) = (3x)2+[4+(−5)]3x+4×(−5)
= 9x2+3x(4–5)–20
= 9x2–3x–20