Answer:
1. No solutions
2. Yes, if Jane buys 3 shirts and yuki buys 4
4. No solutions
5. One, x=6
6. 1-x will be different from 5(x-4) - 6x regardless of the value of x because 5x - 6x is infinitely equal to 1-x but then you will always have to subtract 20, making them infinitely different.
Step-by-step explanation: