Expand the following: \begin{align} a_1 &= \cssId{Step1}{-F_b -mg·sinα= ma_1} \\[3px] &\cssId{Step2}{{} =\frac{-F_b1}{m}-g·sinα=a_1} \\[3px] &\cssId{Step3}{{} = Equation..16..} \\[3px] \end{align}