Linear equations

Question

An executive invests $27000 some at 8% and the rest at 7% annual interest. If he receives an annual return of 2,000, how much is invested at each rate?

Answer 1

let x be the amount invested at 8% annual return

(27000-x) will be the amount invested at 7% annual return

annual return = 2000

2000 = x(0.08) + (27000-x)(0.07)

2000 = 0.08x + 1890 - 0.07x

110 = 0.01x

x= 11000

(27000 - 11000) = 16000

$11000 invested at 8% annual return

$16000 invested at 7% annual return