\(3(t-3)=5(2t+1)\)\(\Rightarrow\) \(3t - 9 = 10t + 5\) (Opening the brackets)\(\Rightarrow\) \(- 9 - 5 = 10t - 3t\)\(\Rightarrow\) \(- 14 = 7t \)\(\Rightarrow\) \(t = \frac{-14}{7}\)\(\Rightarrow\) \(t = -2\)