Jaji's annual income from two investments is $2280. She invested part of his money at 4% nda n amount three times as great at 5%. How much did he invest at each rate? Sir/Maam show your solution pls

Let the principal amount be x

Amount invested at 4% = 0.04x
Amount invested at 5%, three times as much as the amount in = 3 (0.05x)
Total income from the two investments: 2,280

0.04x + 3(0.05x) = 2,280
0.04x + 0.15x = 2 280

0.19 x = 2 280

0.19 x = 2, 280
0.19 0.19

x = 12,000

Amount invested at 4% (x), is $12,000
Amount invested at 5%,
3x = 3 ×12,000 = $ 36,000

To check the interest earned:
at 4% = 0.04 × 12,000 = $ 480
at 5% = 0.05 × 36,000 = $ 1,800

Add the interest: 480 + 180 = 2,280