Zack has two savings accounts with a total of $9,000. he withdrew 10% from one and 60% from the other to buy his girlfriend an engagement ring. if the ring cost $2,175, find the remaining balance in each account.

Originally,
Let x = the balance in the first account.
Let y = the balance in the second account.

The total amount in the two accounts is $9,000, therefore
x + y = 9000                      (1)

Zack withdraws 10% of x and 60% of y for a total of $2,175.
Therefore
0.1x + 0.6y = 2175
or
x + 6y = 21750                   (2)

Subtract (1) from (2).
x + 6y - (x + y) = 21750 - 9000
5y = 12750
y = 2550
From (1), obtain
x = 9000 - 2550 = 6450

The balance in the first account is
0.9*x = 0.9*6450 = $5,805
The remaining balance in the second account is
0.4*y = 0.4*2550 = $1,020

The balance in the first account is $5,805
The balance in the second account is $1,020