Factorize:
(i)`4x^2+12 x y+9y^2`
(ii) `x^4-10 x^2y^2+25 y^4`
(iii)`a^4-2a^2b^2+b^4`

Explanation

(i)`4x^2+12 x y+9y^2`
`=(2x)^2+2(2x)(3y)+(3y)^2`
`=(2x+3y)^2`

(ii) `x^4-10 x^2y^2+25 y^4`
`=(x^2)^2 - 2(x^2)(5y^2) + (5y^2)^2`
`= (x^2 - 5y^2)^2`
`= (x^2 - 5y^2)(x^2 - 5y^2)`

(iii)`a^4-2a^2b^2+b^4`
`=(a^2 )^2 +2a^2b^2 +(b^2)^2 `
`=(a^2 +b^2 )^2`