$6.75 + $4.25 = $10.00
$15.95 - $10.00 = $5.95
The answer is $5.95
You have invested 1200 dollars in your mutual fund and now gained 1333 dollars. First let's solve how much money added to your investment.
=> 1333 - 1200 = 133 dollars was added to your account
=> 133 / 1200 = 0.11
Next, lets convert this to decimal value.
=> 0.11 * 100% = 11% was added to you investment.
To find y, divide the first equation by 2.
y = 4
To find x, use that value for y in the second equation. Add 4, then divide by 2.
15·4 = 2x -4
60 +4 = 2x
64/2 = x = 32
The solution is (x, y) = (32, 4).