a) `x^2-10x + 25 = x^2 - 2.x.5 + 5^2 = (x-5)^2`
b) `1+12x + 36x^2= 1^2 + 2.1.6x + (6x)^2 = (1+6x)^2 `
c) `4x^2 + 4x+1 = (2x)^2 + 2.2x.1 + 1^2 = (2x+1)^2`
d) `(x^2)/4 + 2xy + 4y^2 = (x/2)^2 + 2. x/2 . 2y + (2y)^2 = (x/2 + 2y)^2`
e) `x^3 + 6x^2 + 12x+ 8 = x^3 + 3.x^2 .2 + 3.x . 2^2 + 2^3 = (x+2)^3`
f) `27x^3 -54x^2y+36xy^2-8y^3`
`= (3x)^3 - 3.(3x)^2 .2y + 3.3x .(2y)^2 - (2y)^3 = (3x-2y)^3`