Насчет 1 и 3 упражнений, там все просто, - ставь enough ПЕРЕД существительными, но ПОСЛЕ прилагательных, наречий и глаголов.
2 упражнение:
1. this table is not large enough for me to put..(дальше прямо по тексту, ничего не меняя)
2. this room is to dark for studying
3. our dining room is too small for all of us to...
4. the problem is important enough to...
5. was your composition good enough to...
6. the task is too hard for me to...
7. is the light bright enough for you to...