I'm not sure I understand the question thoroughly but I'll try...
Let's make "x" the amount in the account.
$40 * 4 = $160.
After four months: x - $160
Answer:
x=-1
Step-by-step explanation:
-8x+32=40
-8x=8
Yes
3x...
There is nothing else to do an equation with..
4 14/25
4.56 = 4 56/100 = 4 14/25