Question

The work of a student trying to solve the equation 2(2x − 3) = 6 + 2x + 4 is shown below:

Step 1: 2(2x − 3) = 6 + 2x + 4
Step 2: 4x − 3 = 10 + 2x
Step 3: 4x − 2x = 10 + 3
Step 4: 2x = 13
Step 5: x = 6.5

In which step did the student first make an error and what is the correct step? (4 points)


Step 2: 4x − 6 = 10 + 2x

Step 2: 4x − 3 = 2 + 2x

Step 3: 4x + 2x = 10 + 3

Step 3: 4x − 2x = 10 - 3

Answer 1

The student first made an error in Step 3. The correct step should be:

Step 3: 4x - 2x = 10 + 3