Financial mixture problems

Question

Sam has $120,000 invested in an account that pays 4.5% interest. How much would he need to invest in an account that pays 5.7% interest to raise his combined yield to 5%?

Answer 1

(4.5%)(120000) + 5.7%x = 5%(120000 + x)

0.045(120000) + 0.057x = 0.05(120000 + x)

 

Can you solve this equation?