Answer:
1. No
2. Yes
3. No
Explanation:
1.
We know that c = 7, so we plug it in to prove if the equation is true.

The variable is not a solution.
2.
We know a = 30, so we plug it in to prove if the equation is true.

The variable is a solution.
3.
We know y = 4.1, so we plug it in to prove if the equation is true.

The variable is not a solution.