Question

solve using suitable identity a)(3x+7)2​

Answer 1

Solution :-

$By \: using \: identity \: : - \: \: {(a + b)}^{2} = > {a}^{2} + {b}^{2} + 2ab \\ \\ {(3x + 7)}^{2} \: = > ({3x})^{2} + ( {7})^{2} + 2(3x)(7) \\ \\ {(3x + 7)}^{2} \: = > {9x}^{2} + 49 + 42x$

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Answer 2

Answer :

• (3x + 7)² = 9x² + 49 + 42x.

Given :

• (3x + 7)²

To find :

• Value of expression

Solution :

Given,

• (3x + 7)²

⤍ (3x + 7)²

We know that

• (a + b)² = a² + b² + 2ab

Where ,

• a is 3x
• b is 7

⤍ (a + b)² = a² + b² + 2ab

⤍ (3x + 7)² = (3x)² + (7)² + 2(3x)(7)

⤍ (3x + 7)² = 9x² + 49 + 2(21x)

⤍ (3x + 7)² = 9x² + 49 + 42x

Hence,

• (3x + 7)² = 9x² + 49 + 42x.