[tex] \frac{a+b+c}{2} = -33 =\ \textgreater \ a+b+c = -66 \\ \frac{a+b}{2} =-29 =\ \textgreater \ a+b = -58 \\ a+b+c = -66 \\ -58+c=-66 \\ c=-66-(-58) \\ c= -66+58 \\ c=8 \\ \\ \frac{a+a+1+a+2}{3} =7 =\ \textgreater \ 3a+3 = 21 \\ 3a=21-3 \\ 3a=18 \\ a=18:3 \\ a=6 , a+1 = 7 ,a+2=8[/tex]
