Hello, lahoo!

Person X invested $10,000 in three accounts.

. . Account A pays 4.5% interest.

. . Account B pays 6.2% interest.

. . Account C pays 3.5% interest.

X decides to invest into account B double the sum of the other two accounts.

When the first dividends came, they earned $549 interest.

How much invested into each account?

If we organize the information, everything is clearer . . .

. .

In the second column, we have: .

In the last column: .

Multiply by 1000: .

Solve the system of equations: .

. .

And we get: . in account

Substitute into [1]: . in account

Then: . in account