for:
[tex]\begin{gathered} r(t)=730 \\ 5t^2+5t+630=730 \\ so\colon \\ 5t^2+5t-100=0 \end{gathered}[/tex]Divide both sides by 5:
[tex]t^2+t-20=0[/tex]Factor:
The factors of -20 which sum to 1, are -4 and 5 so:
[tex](t-4)(t+5)=0[/tex]So:
[tex]\begin{gathered} t=4 \\ or \\ t=-5 \end{gathered}[/tex]Since a negative year wouldn't make any sense:
[tex]t=4[/tex]Therefore, the company revenue will be $730 for the year:
[tex]1998+t=1998+4=2002[/tex]Answer:
2002