To evaluate the limit as \( t \) approaches infinity, we focus on the highest degree terms in the numerator and the denominator. The highest degree term in both the numerator and the denominator is \( t^6 \). By dividing every term by \( t^6 \), we simplify the expression and find the limit.
Step 1: Identify the Limit
We need to evaluate the limit:
\[
\lim_{t \rightarrow \infty} \frac{t^{6} + 2t - 8}{5t^{6} + 3t^{3}}.
\]
Step 2: Simplify the Expression
To simplify the expression, we divide every term in the numerator and the denominator by \( t^{6} \):
\[
\frac{t^{6}/t^{6} + 2t/t^{6} - 8/t^{6}}{5t^{6}/t^{6} + 3t^{3}/t^{6}} = \frac{1 + \frac{2}{t^{5}} - \frac{8}{t^{6}}}{5 + \frac{3}{t^{3}}}.
\]
Step 3: Evaluate the Limit
As \( t \) approaches infinity, the terms \( \frac{2}{t^{5}} \), \( \frac{8}{t^{6}} \), and \( \frac{3}{t^{3}} \) all approach \( 0 \). Thus, the limit simplifies to:
\[
\frac{1 + 0 - 0}{5 + 0} = \frac{1}{5}.
\]