Let x be the amount invested at 12% then the amount invested at 6% is 1400-x.
The amount returned is 11% of $500=$55.
The amount returned on x is 0.12x.
The amount returned on 1400-x is 0.06(1400-x).
The amount to be returned at 9% on $1900=$171.
So 55+0.12x+0.06(1400-x)=171.
55+0.12x+84-0.06x=171.
0.06x=171-139=32, x=32/0.06=3200/6=1600/3=$533.33.
$533.33 to be invested at 12%, $866.67 at 6%.