Question

using an appropriate identity expand
$(7a - 3 {b}^{2}$

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Answer 1

( 7a - 3b ) ²

Using the identity

• ( a - b ) ² = a² - 2ab + b²

( 7a ) ² - 2 x 7a x 3b + ( 3b ) ²

49a² - 42ab + 9b² ➡ Answer