Can anyone help me with these questions? Please

1. ac - bc + ad - bd
2. xy - 3x - 8y + 24
3. 4x^2 + 20x + 5y +xy
4. 48x^2y + 20xz +12xy + 5z

Do some grouping and factoring. For instance, the first..

ac - bc + ad - bd
(a-b)c + (a-b)d
(a-b)(c+d)