(1)x^2+x+1/4
=(x+1/2)²
(2)25x^2+20xy+4y^2
=(5x+2y)²
(3)a^3-10a^2+25a
=a(a²-10a+25)
=a(a-5)²
(4)(x^2+4y^2)^2-16x^2y^2
=(x²+4y²-4xy)(x²+4y²+4xy)
=(x-2y)²(x+2y)²
(1)x^2+x+1/4
=(x+1/2)²
(2)25x^2+20xy+4y^2
=(5x+2y)²
(3)a^3-10a^2+25a
=a(a²-10a+25)
=a(a-5)²
(4)(x^2+4y^2)^2-16x^2y^2
=(x²+4y²-4xy)(x²+4y²+4xy)
=(x-2y)²(x+2y)²