\[\boxed{\text{850.}\text{\ }еуроки - ответы\ на\ пятёрку}\]
\[\textbf{а)}\ 4x² + 12x + 9 = (2x + 3)^{2} = (2x + 3)(2x + 3)\]
\[\textbf{б)}\ 25b² + 10b + 1 = (5b + 1)^{2} = (5b + 1)(5b + 1)\]
\[\textbf{в)}\ 9x² - 24xy + 16y^{2} = (3x - 4y)^{2} = (3x - 4y)(3x - 4y)\]
\[\textbf{г)}\frac{1}{4}m² + 4n² - 2mn = \left( \frac{1}{2}m - 2n \right)^{2} = \left( \frac{1}{2}m - 2n \right)\left( \frac{1}{2}m - 2n \right)\]
\[\textbf{д)}\ 10xy + 0,25x² + 100y² = (0,5x + 10y)^{2} = (0,5x + 10y)(0,5x + 10y)\]
\[\textbf{е)}\ 9a² - ab + \frac{1}{36}b^{2} = \left( 3a - \frac{1}{6}b \right)^{2} = \left( 3a - \frac{1}{6}b \right)\left( 3a - \frac{1}{6}b \right)\]