Show me the steps to solve $4.\backslash ($ A $\backslash )$ uniform rod of length $\backslash ($ L $\backslash )$ and mass $\backslash (2$ M $\backslash )$ rests over two supports $\backslash ($ A $\backslash )$ and $\backslash ($ B $\backslash ).$ A particle having mass, $\backslash ($ M $\backslash )$ is placed at the right end. Find the reactions at supports $\backslash ($ A $\backslash )$ and $\backslash ($ B $\backslash ).$