What is the first step when rewriting y is equal to 3 x squared plus 9 x minus 18 in the form y is equal to A times open paren x minus h close paren squared plus k ?

To rewrite the quadratic in vertex form by completing the square, first factor the leading coefficient from the terms containing x. In 3x² + 9x, the common factor is 3, so write the expression as 3(x² + 3x) − 18. Therefore, the first step is to factor 3 from 3x² + 9x.

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