Answer:
He made a mistake in the second line.
Step-by-step explanation:
He factored out x out of 6-2x and 5+4x, which is not possible because there is not an x in both 6 and 5.
The intersection of two sets A and B is defined as the set composed by the elements appearing in both A and B.
So, the intersection is

Because all the other numbers do not belong to both sets:
- 2, 3 and 7 belong to A alone
- 13, 15 and 17 belong to B alone
- 5 and 11 belong to both A and B
Answer:
1/2(x+7)
Step-by-step explanation:
I hope this helps. Have a good day.