Question

Identify the mistake in the solution below and explain how

to correct it. Determine the correct answer.
Algebra
3x - 5+ 3x = x + 8-x-1
6x – 5 = 2x + 7
4x - 5 = 7
4x = 12
x = 3
Steps
original problem
combine like terms
subtract 2x from both sides
add 5 to both sides
divide both sides by 4
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Answer 1

Mistake is on second line.

x = 2

Explanation:

The first two lines are (I added the boldface):

3x - 5 + 3x = x + 8 - x - 1

6x – 5 = 2x + 7

The first line has x and -x. They add to 0.

The second line on the right side should have just 7, but the x and -x of the first line were incorrectly added together giving 2x.

The second line should be:

6x - 5 = 7

Add 5 to both sides.

6x = 12

Divide both sides by 6.

x = 2