Systems of equation

Question

Ms. Chaminiti has some money invested at 4% and three times as much invested at 6%.her total annual income from two investments is 1100. How much is invested at each rate?

Answer 1

0.04x + 0.06(3x) = 1100

0.04x + 0.18x = 1100

0.22x = 1100

22x = 110000

x = 110000/22 = 5000

$5000 invested at 4%

$15000 invested at 6%