For example, a ==b ---> a * c == b * c. Thanks.
MultiplySides[a == b, c]
$\begin{array}{cc} \{ & \begin{array}{cc} a c=b c & c\neq 0 \\ a=b & \text{True} \\ \end{array} \\ \end{array}$
MultiplySides[a == b, c, GenerateConditions -> False]
$a c=b c$
In version 11.3 we have MultiplySides:
MultiplySides
MultiplySides[x/3 == 7, 3]
In earlier version you can Map the multiplication:
Map
Map[3 # &, x/3 == 7]
function Map is what I am looking for. Thanks.
