The way to find slope intercept form is simple. All you have to do is isolate the Y whether a number is attached to the number or not. In some cases, this will solve the problem, but in other cases it wont. If it does not, then divide/multiply the number on both sides to isolate the Y completely. Here are the answers to your questions.
1. y = (2/7)x - 2
2. y = x - 5
3. y = 2x - 6
4. y = 4x +1 (The Y was already isolated)
5. y = -2x + 6
6. y = (2/3)x - 1