Find the mistake in solving two-step equations

The  exercise appears under the 7th grade (U.S.) Math Mission. This exercise solves linear equations with possible errors that need to be identified.

Types of Problems
There is one type of problem in this exercise:


 * 1) Find the error in the solution: This problem provides a algebraic equation and a solution to that equation that may or may not have an error. The student is asked to find the step where an error occurred (if there is one).Ftmistse1.png

Strategies
Knowledge of the distributive property and the process of solving linear equations are encouraged to ensure success on this exercise.
 * 1) The solutions occasionally divide rather than distribute when either path may arrive at the correct answer.
 * 2) One can check the proposed solution, and if it is correct than the process was likely correct also.

Real-life Applications

 * 1) Solving equations shows up in many science, social science, and of course mathematics courses.