3.
[tex]a) \ a^{2}+2ab+b^{2} = (a+b)^{2}\\\\b) \ 4x^{2}+4ax + a^{2} = (2z+a)^{2}\\\\c) \ 4a^{2}+12ab + 9b^{2} = (2a+3b)^{2}\\\\d) \ 9a^{2}+3a+\frac{1}{4} = (3a+\frac{1}{2})^{2}\\\\e) \ a^{2}-4ab + 4b^{2} = (a-2b)^{2}\\\\f) \ 16x^{2}-8xy + y^{2} = (4x-y)^{2}\\\\g) \ 1-6a+9a^{2} = (1-3a)^{2}\\\\h) \ \frac{1}{4}x^{2}-\frac{1}{3}xy+\frac{1}{9}y^{2} = (\frac{1}{2}x+\frac{1}{3}y)^{2}[/tex]
[tex]i) \ x^{2}-4y^{2} = (x+2y)(x-2y)\\\\j) \ 16a^{2}-9 = (4a+3)(4a-3)\\\\k) \ 25-36x^{2} = (5+6x)(5-6x)\\\\l) \ \frac{1}{25}x^{2}-9y^{2} = (\frac{1}{5}x+3y)(\frac{1}{5}x - 3y)[/tex]
