Carlos made the mistake that he did not combine like terms (3 x and 2 x) properly and did not use addition property of equality.
<u>Step-by-step explanation:</u>
Carlos did the work as 3 x + 2 x - 6 = 24
We need to find his mistake that he made in above given.
Here, he did not add the like terms (3 x and 2 x)
3 x + 2 x = 5 x
Therefore, his work should be
5 x - 6 = 24
Also, he did not use addition property of equality. It means the equation remains same even though the same number gets added on both sides. It would be
5 x - 6 = 24
+ 6 = + 6
-----------------------
5 x = 30
Dividing 30 by 5, we get answer as '6'. Hence,
= 6
So, stated the above two are the mistakes found in carlos work.