Question

Benjamin solved the following equation: 4x − 2x + 8 = 6(x + 4) Step Work Justification 1 4x − 2x + 8 = 6x + 24 Combine like terms 2 2x + 8 = 6x + 24 Combine like terms 3 −4x + 8 = 24 Subtraction property of equality 4 −4x = 16 Subtraction property of equality 5 x = −4 Division property of equality Which step has an incorrect justification?

Answer 1

For this case we have the following expression:
 4x - 2x + 8 = 6 (x + 4)
 The first step is:
 4x - 2x + 8 = 6x + 24
 The first step is, correct.
 However, the justification "Combine like terms" is NOT correct.
 The correct justification is:
 Distributive property of multiplication.
 Answer:
 A step that has an incorrect justification is:
 Step 1