We can tell any number is solution of any equation
by plugging that number into equation
and then we check whether it satisfies the given equation
For example:
(1)
Let's assume we have given solution x=1 of

now, we can plug x=1 to verify it




we can see that both sides are equal to 0
so, x=1 will be solution of this equation
(2)
Let's assume we are given x=2 is the solution
now, we can verify it in same way

now, we can plug x=2 to verify it




we know that -1 can not be equal to 0
so, x=2 does not satisfy this equation
so, x=2 can not be solution of this equation