Algebra 1 math question

Question

After one year, you earned $1705.20 in interest on your nest egg you invested in two accounts. In the first account you invested $16800 at 2.5%. The second account has an interest rate of 6.3%. How much was invested in this account?

Answer 1

1705.20 = 16800 * 0.025 + 0.063*X

(1705.20 - 16800*0.025) / 0.063 = x

x=20400