Question

The work of a student to solve the equation 2(3x − 4) = 8 + 2x + 4 is shown below:

Answer 1

The correct answer is "Step 2; 6x − 8 = 12 + 2x."

The step that the student first make an error is at the 2nd step. The correct step should be 6x − 8 = 12 + 2x.

Finishing the steps:
Step 1: 2(3x − 4) = 8 + 2x + 4
Step 2: 6x − 8 = 12 + 2x.
Step 3: 4x = 20
Step 4: x = 5

Answer 2

Answer:

Step 2; 6x − 8 = 12 + 2x

Step-by-step explanation:

Step 1: Write the equation

$2(3x-4)=8+2x+4$

Step 2: Apply distributive property to the left side and sum the constants to the right side

$2(3x-4)=(8+4)+2x\\(2*3x)-(2*4)=12+2x\\6x-8=12+2x$

Step 3: Subtract 2x from both sides and add 8 to both sides:

$6x-8=12+2x\\6x-2x+8-8=12+8+2x-2x\\4x=20$

Step 4: Divide both sides by 4:

$x=\frac{20}{4} =5$