The problems that have infinite solutions are:
2. 7x + 3 = 7x + 3 (same equation on both sides)
5. 3x + 18 = 5x + 8 (equation simplifies to 0 = 0)
The problems that have no solution are:
1. 2x + 3 = 2x + 7 (equation simplifies to 3 = 7, which is not true)
4. 5x + 5 = 5x + 4 (equation simplifies to 5 = 4, which is not true)
The problems that have one solution are:
3. 4x + 22 = 8x + 10 (solving gives x = 3)
6. 3(4x + 8) = 4(3x + 6) (solving gives x = -6)