\( a_{1} + a_{3} = 6 \Rightarrow a_{1} + (a_{1} + 2d) = 6 \Rightarrow 2a_{1} + 2d = 6 \xrightarrow{ \div 2 } a_{1} + d = 3 \Rightarrow a_{2} = 3 \) \( a_{2} \times a_{5} = 54 \Rightarrow 3 \times a_{5} = 54 \Rightarrow a_{5} = \frac{54}{3} = 18 \) \( d = \frac{a_{5} - a_{2}}{5 - 2} = \frac{18 - 3}{3} = \frac{15}{3} = 5 \) \( a_{2} = 3 \Rightarrow a_{1} + d = 3 \Rightarrow a_{1} + 5 = 3 \Rightarrow a_{1} = -2 \)