Answer:
$4600
Step-by-step explanation:
Write an equation to represent the problem.
Interest is calculated by multiplying the interest rate with the investment. Multiplying each of the rates (2%, 7% and 9%) in decimal form with the investment amount is equal to the annual interest, (828).
Convert a percentage to decimal form by dividing by 100:
2% ÷ 100 => 0.02
7% ÷ 100 => 0.07
9% ÷ 100 => 0.09
let "P" represent the amount of money for the total investment
0.02P + 0.07P + 0.09P = 828
Use the equation to solve for "P". Simplify by collecting like terms (numbers that have the same variable) then isolate "P" by moving the other numbers to the right side. To move a number to the other side, do it's reverse operation to both sides of the equation. (The reverse of multiplying is dividing).
0.02P + 0.07P + 0.09P = 828 Collect like terms
0.18P = 828 Isolate "P"
0.18P/0.18 = 828/0.18 Divide both sides by 0.18
P = 828/0.18 "P" is isolated because 0.18 cancelled out. Simplify.
P = 4600 Total investment
Therefore the total investment is $4600.
