Question

9b2
3b2
–9b2
–3b2
.... ​

Answer 1

Ответ:

$( \frac{2}{3} - 3b)( \frac{2}{3} + 3b) - \frac{4}{9} = \\ {( \frac{2}{3} )}^{2} - {(3b)}^{2} - \frac{4}{9} = \\ \frac{4}{9} - 9 {b}^{2} - \frac{4}{9} = - 9 {b}^{2} \\ otvet \: \: - 9 {b}^{2}$

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