Answer :
Use the acronym DCOAM [Distribute, Combine like terms, one side the variable, Add or subtract, Multipy or divide]
A has only one solution , x= 30
B is an identity because if you combine like terms and add, you get
25-4x=25-4x
C has no solutions
A has only one solution , x= 30
B is an identity because if you combine like terms and add, you get
25-4x=25-4x
C has no solutions