## Algebra and Trigonometry 10th Edition

$-(3x-1)^{2}$
Expression : $-9x^{2}+6x-1 = -(9x^{2}-6x+1)$ By the well known formula $(a-b)^{2} = a^{2} -2ab +b^{2}$ $(9x^{2}-6x+1) = (3x)^{2}-2(3x)(1)+1^{2} = (3x-1)^{2}$ Hence, $-9x^{2}+6x-1 = -(9x^{2}-6x+1) = -(3x-1)^{2}$