Answer
$120\div(-10)\cdot2-3(4-5)=-21$
Work Step by Step
According to the order of the operations simplify as follows:
$\begin{array}\,{120\div(-10)\cdot2-3(4-5)}&{}=120\div(-10)\cdot2-3(-1)
\newline &{}=-12\cdot2-3(-1)
\newline&{}=-24+3
\newline&{}=-21\end{array}$