[tex]21200 + 415(y)[/tex]
[tex]27000 = 21200 + 415(y)[/tex]
[tex]27000 - 21200 = 21200 - 21200 + 415(y)[/tex]
[tex]5800 = 415(y)[/tex]
[tex] \frac{5800}{415} = \frac{415(y)}{415} [/tex]
[tex]13.9759..... = y[/tex]
[tex]it \: will \: take \: about \: 14.0 \: years[/tex]