$\huge x^{2} + 4x +4 = (x+\square)(x+\square)$
$x^{2} + 4x +4 = (x+\square)(x+\square)=(x+2)(x+2)=(x+2)^{2}$
$\huge 9-12x +4x^{2} = (3-\square)(3-\square)$
$9-12x +4x^{2} = (3-\square)(3-\square)=(3-2x)(3-2x)=(3-2x)^{2}$
$\huge 25y^{2} -4= (\square-\square)(\square+\square)$
$25y^{2} -4 = (\square-\square)(\square+\square)=(5y-2)(5y+2)$
$\huge x^{2}-(2x-1)^{2} = (\square-1)(\square+1)$
$x^{2}-(2x-1)^{2} = (\square-1)(\square+1)=\left [x-(2x-1)\right ]\left [x+(2x-1)\right ]=(x-2x+1)(x+2x-1)=(-x+1)(3x-1)$
$\huge x^{2} + 6x + 9 =$
$x^{2} +6x+9 =(x+3)^{2}$
$\huge x^{2} - 4xy +4y^{2} =$
$x^{2} - 4xy +4y^{2} = (x-2y)^{2}$
$\huge m^{4}n^{2} - 8m^{2}np+16p^{2} =$
$m^{4}n^{2} - 8m^{2}np+16p^{2}=(m^{2}n-4p)^{2}$
$\huge 0,01p^{6}-0,2p^{3}m^{2}n +m^{4}n^{2} =$
$0,01p^{6}-0,2p^{3}m^{2}n +m^{4}n^{2}=(0,1p^{3}-m^{2}n)^{2}$
$\huge 25^{2} - 1=$
$25x^{2} - 1= (5x-1)(5x+1)$
$\huge 169x^{2} - 81y^{2}=$
$169x^{2} - 81y^{2}= (13x-9y)(13x+9y)$
$\huge 0,09m^{2} - 4n^{2}=$
$0,09m^{2} - 4n^{2}= (0,3m-2n)(0,3m+2n)$
$\huge 64x^{2} - (7x+6y)^{2}=$
$64x^{2} - (7x+6y)^{2}=\left [8x-(7x+6y)\right ]\left [8x+(7x+6y)\right ]=(8x-7x-6y)(8x+7x+6y)=(x-6y)(15x+6y)$
$\huge(3x+4y)^{2} - (5x-9y)^{2}=$
$(3x+4y)^{2} - (5x-9y)^{2}=\left [(3x+4y)-(5x-9y)\right ]\left [(3x+4y)+(5x-9y)\right ]=(3x+4y-5x+9y)(3x+4y+5x-9y)=(-2x+13y)(8x-5y)$