Question 1012921
Call what Olivia and Carl have, x and y.  Thus we have
x = y + 30  and
(x - 7) + (y - 7) = x
A few ways to solve this, but let us substitute the first equation into the second and we get
(y+30 - 7) + (y - 7) = y + 30
2y + 16 = y + 30
Now subtract y from both sides, then subtract 16...
y + 16 = 30
y = $14 for Carl
x = y + 30 = $44 for Olivia