Question

please find this question
$(7a - 3b) {}^{2}$

Answer 1

( 7a - 3b )^2

using formula --
( a - b )^2 = a^2 + b ^2 - 2ab

= 49a^2 + 9b^2 - 42ab

Answer 2

HEYA!!
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$= > > using \: identity \: (a - b) {}^{2} = a {}^{2} + b {}^{2} - 2ab < < = \\ \\ \\ (7a - 3b) {}^{2} = (7a) {}^{2} + (3b) {}^{2} - 2 \times 7a \times 3b \\ \\ = > 49a {}^{2} + 9b {}^{2} - 42ab$
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