Faire les calculs suivants en détaillant les étapes (penser à simplifier les fractions quand c'est possible).
\begin{parts}
    \begin{multicols}{4}
            \Block{set e = Expression.random("{a} / {b} + {c} / {d}", ["gcd({b},{d})==1"], val_min = 2, val_max=15)}
            \part $A = \Var{e}$
            \begin{solution}
                \begin{eqnarray*}
                    \Var{e.simplify().explain() | calculus(name = "A")}
                \end{eqnarray*}
            \end{solution}
            \columnbreak

            \Block{set e = Expression.random("{a} / {b} * {c}/{d}", ["{b} > 1", "{d} > 1"])}
            \part $B = \Var{e}$
            \begin{solution}
                \begin{eqnarray*}
                    \Var{e.simplify().explain() | calculus(name = "B")}
                \end{eqnarray*}
            \end{solution}

            \columnbreak

            \Block{set e = Expression.random("{a} / {b} + {c} / {b}", ["{b} > 1"])}
            \part $C = \Var{e}$
            \begin{solution}
                \begin{eqnarray*}
                    \Var{e.simplify().explain() | calculus(name = "C")}
                \end{eqnarray*}
            \end{solution}
            \columnbreak

            \Block{set e = Expression.random("{a} / {b} * {c}", ["{b} > 1","{c} > 1", "gcd({c},{b})==1"])}
            \part $D = \Var{e}$
            \begin{solution}
                \begin{eqnarray*}
                    \Var{e.simplify().explain() | calculus(name = "D")}
                \end{eqnarray*}
            \end{solution}
    \end{multicols}

\end{parts}