Đáp án:
$a) 25a^2 +10a+1$
$ = (5a+1)^2$
$= (5a+1)(5a+1)$
$b) 10ab + 0,25a^2 +100b^2$
$ = 0,25a^2 + 2. 0,5a .10b +100b^2$
$= (0,5a +10b)^2$
$ = (0,5a+10b)(0,5a+10b)$
$c) 9x^2-24x+16y^2$
$ = (3x -4y)^2$
$= (3x-4y)(3x-4y)$
$d) 9x^2-xy+\dfrac{1}{36}y^2$
$ = (3x - \dfrac{1}{6}y)^2$
$ = (3x-\dfrac{1}{6}y)(3x-\dfrac{1}{6}y)$