помогите с примерами
-30+20:(-5)
3.9* 4.58 +3.9*5.42
1 1/11 * (1/4+2/3) -1.2

1)-30+20:(-5)= -30+(-4)= -30-4=-342)3,9*4,58+3,9*5,42=3,9 * ( 4,58+5,42)= 3,9*10=393)11/11*(1/4+2/3)-1,2= 1 * 11/12-6/5= -17/60