95.7k views
1 vote
The work of a student to solve the equation 3(3x − 4) = 8 + 2x + 5 is shown below: Step 1. 3(3x − 4) = 8 + 2x + 5 Step 2. 6x − 7 = 13 + 2x Step 3. 6x − 2x = 13 + 7 Step 4. 4x = 20 Step 5. x = 5 In which step did the student first make an error and what is the correct step? Step 2, 9x − 12 = 13 + 2x Step 2, 9x − 4 = 2(6 + x + 3) Step 3, 6x + 2x = 13 + 7 Step 3, 6x − 2x = 13 − 7

User Let
by
8.6k points

2 Answers

3 votes
welll 12 is the power of 12 so the sum of 32 is 12
User Seact
by
7.9k points
4 votes
Student made an error in step 2. Correct step is 9x - 12 = 13 + 2x.
User Shital Shah
by
8.0k points