Answer:
1.
(for example, 7, 1);
2.
(for example, 5, 6);
3.

Explanation:
Simplify the given left side of each equation:

The equation
- has no solution if it is impossible for the equation to be true no matter what value we assign to the variable x;
- has infinitely many solutions if any value for the variable x would make the equation true;
- has exactly one solution.
No solutions: The right side of the equation should be of the form
where
For example,
In this case, the equation will take look
This statement cannot be correct for any value of the variable x, so the equation has no solutions.
Infinitely many solutions: The right side should be exactly the same as the left side:
This statement is correct for all values of the variable x, so the equation has infinitely many solutions.
One solution: The right side of the equation should be of the form
where
For example,
In this case,