a, 2012 x 24 + 77 x 2012 - 2012
= 2012 x (24 + 77 - 1)
= 2012 x 100
= 201 200
b, 33 x 76 + 84 x 27 + 32 x 3 x 40
= 27 x 76 + 84 x 27 + 27 x 40
= 27 x (76 + 84 + 40)
= 27 x 200
= 5400
c,
C = \(\dfrac{2^{83}+2^{84}+2^{85}}{2^{82}+2^{81}+2^{80}}\)
C = \(\dfrac{2^{83}.\left(1+2+2^2\right)}{2^{80}\left(2^2+2+1\right)}\)
C = 23
C = 8