[tex]a) 2500-5\cdot12:2+400\cdot2= \\ =2500-5 \cdot 6+800= \\ =2500-30+800= \\ =2470+800= \\ =3270 \\ b). (180+248)\cdot500:2-1009= \\ =428 \cdot 500:2-1009= \\ =428 \cdot 250-1009= \\ =107000-1009= \\ =105991[/tex]
[tex]c). 232+[48\cdot25+(540\cdot11-82\cdot5)\cdot10]= \\ =232+[1200+(5940-410) \cdot 10]= \\ =232+(1200+5530 \cdot 10)= \\ =232+(1200+55300)= \\ =232+56500= \\ =56732[/tex]