I think the answer is 120.
This is a simple formula:(a-b)*(a+b)= a^2-b^2
And it goes like this for your example: (a-1)*(a+1)=a*a+a-a-1*1=a^2-1^2=a^2-1
Chilee i DONT know I’m just trying to get these points
Leroi’s account
$100
After first deposit = $100+$10=$110
After second deposit= $110 + $10 = $120
Sylvia’s account
$100
10% of $100 is $10
After first deposit = $100+ $10 = $110
10% of $110 = $11
After second deposit = $110 + $11 = $121
Therefore after their first deposit, both will have the same value in their accounts.
But after the second deposit, Sylvia will have 1$ more in her account than Leroi.