Firstly we need to find out how much is 5% from $5700:
5700 * 5% =
= 5700 * 5/100 =
= 57 * 5 =
= 285
$1077 - $285 = $792
So now we need to find out how much should be invested at 9% annual simple interest to earn $792.
792 = 9% from x
792 = 9/100 x / * 100 (both sides)
79200 = 9x / ÷ 9 (both sides)
x = 8800
Answer: When investing $5700 at 5% annual simple interest, also $8800 at 9% annual simple interest should be invested to have the total yearly income of $1077.