Factorize each of the following expressions:
(i) `9x^2-4y^2`
(ii) `36 x^2-12 x+1-25 y^2`

Explanation

(i)`9x^2-4y^2`
`=(3x)^2+(2y)^2+12xy-12xy`
`=[(3x)^2+(2y)^2+12xy]-12xy`
`=(3x+2y)^2-12xy`

(ii) `36 x^2-12 x+1-25 y^2`
`=(6x)^2 - 2(6x)(1) + (1)^2 - (5y)^2`
`=(6x - 1 )^2 - (5y )^2`
`=(6x - 1 - 5y ) ( 6y - 1 + 5y )`
`=(6x - 5y - 1 ) ( 6x + 5y - 1)`