Question 1091968
Since the first three terms and the last three terms sum to 4x. 
The first term and the last terms must contain the 2x term and the middle terms contain the x term. 
So then for the constant term, there are 12 possible combinations. 
Six combinations of the middle 3 terms and two combinations of the outer terms.
Here's one,
(2,1)
(1,2)
(1,5)
(1,-3)
(2,-3)
So then the top three sums would be
(2+1+1,1+2+5)
(4,8)
4x+8
The bottom three sums would be,
(1+1+2,5-3-3)
(4,-1)
4x-1
You can apply some logic rules since each sum shares one term (the middle one) and narrow it down.
Work it our and see which combination works.
I used EXCEL to simplify but paper and pencil works just as well.