what is -2.9x=-11.31 ???
\(-2.9 x=-11.31\ \ \ \ |divide\ both\ sides\ by\ (-2.9)\\\\\frac{-29x}{-2.9}=\frac{-11.31}{-2.9}\\\\x=\frac{11.31}{2.9}\\\\\huge\boxed{x=3.9}\)