Class 9th math 4.4 solution english PCTB

Question # 01: Find the square root of the following polynomials by factorization method:

\((iii)\) \(\;\) \(36a^2+84a+49 \)

Solution:

$36a^{2} +84a+49$

$=36a^{2} +84a+49$

$=( 6a)^{2} +2( 6a)( 7) +7^{2}$

$\displaystyle =( 6a+7)^{2}$

Taking square root, we have

$ $$\sqrt{36a^{2} +84a+49} =\pm \sqrt{( 6a+7)^{2}}$

$\displaystyle \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ =\pm ( 6a+7)$

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