Hello,
Question:
Keisha solved the following equation:
4x − 2x + 8 = 6(x + 4)
Which step has an incorrect justification? (Make sure to type only the number of the step into the blank: 1, 2, 3, 4 or 5)
Correct Solution:
x − 2x + 8 = 6(x + 4)
4x + −2x + 8 = (6) (x) + (6) (4) (Distribute)
4x + −2x + 8 = 6x + 24
(4x + −2x) + (8) = 6x + 24 (Combine Like Terms)
2x + 8 = 6x + 24
2x + 8 = 6x + 24
Subtract 6x from both sides.
2x + 8 − 6x = 6x + 24 − 6x
−4x + 8 = 24
Subtract 8 from both sides.
−4x + 8 − 8 = 24 − 8
−4x = 16
-4 x -4 = 16
x = -4
Answer:
Where keisha went wrong was forgeting to subtract 6x to both sides.
Incorrrect step is #3
The solution to the equation is correct.
on the line - 4x + 8 = 24 to the next line
- 4x = 16
4 should be Subtraction property of equality and not addition property of equality
