Answer:
5x+12=5x-7
Step-by-step explanation:
If both x's on each are the same number, but with different constants, then the equation is unsolvable. If 5x+12=y, then 5x-7 can't also equal y because they are two different equations.
With all other equations, although some come out irrational, they are solvable and have a solution to them.
