EOY.........Cash Flow
0..............Q
1..............-10
2..............-10
3..............-10
4..............-10
5..............-10
6..............-Q
7...............20
8...............20
9...............20
10.............20

use reference point EOY #6. Show the equivalent value of each group of transaction at reference point #6

how do i do this? cause i got all the way to having

Q at #0 = 1.772Q
Group A -10's = 67.155
Group B 20's = 63.4

but how do i get the answer for Q
on my paper it says Q = 4.863
but i just can't seem to figure out how to get that..