Answer:
Step-by-step explanation:
[tex]3(* + 4) - 2 (1 - 1);\\\\3(\times +4)-2(1-1)\\\\3\left(4\right)-2\left(1-1\right)\\\\\mathrm{Remove\:parentheses}:\quad \left(a\right)=a\\=3\times \:4-2\left(1-1\right)\\\\3\times \:4=12\\2\left(1-1\right)=0\\\\=12-0\\\\=12[/tex]