Relacione as colunas: a) x² – 6x + 8 ( ) (x + 3) (x + 1) b) x² – 5x + 4 ( ) (x – 2) (x – 4) c) x² + 2x – 3 ( ) (x – 4) (x – 1) d) x² + 4x + 3 ( ) (x + 3) (x – 1)