Answer:
The system has an infinite set of solutions 
Step-by-step explanation:
From the first equation:




Replacing on the second equation:




This means that the system has an infinite number of solutions, considering:



The system has an infinite set of solutions 
Answer:
8by + 2ax - 4bx - 4ay
Step-by-step explanation:
I assume you mean expand so:
(a - 2b)(3x - 5y) + (2b - a)(x - y)
3ax - 5ay - 6bx + 10by + 2bx - 2by - ax + ay
Now collect like terms:
2ax - 4ay - 4bx + 8by
This is your answer but in a better order:
8by + 2ax - 4bx - 4ay
True. If they never intersect then they must have the same slope and are parallel
The percent of change is 73.33 percent