Priorities: parentheses, brackets, braces

Go ! $2\cdot [4-(1-3)] = 2\cdot [4-(-2)] = 2\cdot [4+2] = 2\cdot 6 = 12$ $2-(1-2) $ =   $2(1-2) $ =   $-2-[1-(1-2)] $ =   $2\{ 1- [1-(1-2)] \} $ =