Factorize:
(i))`x^2+8x+15`
(ii) `x^4+x^2+1`

Explanation

(i)`x^2+8x+15`
`=x^2−5x−3x+15`
`=x(x−5)−3(x−5)`
`=(x−5)(x−3)`

(ii) `x^4+x^2+1`
`=(x^2 )^2+2(x^2)^(1)+1^2−x^2`
`=(x^2+1) 2−x^2`
`=(x^2+1−x)(x^2 +1+x)`