5.
c)13/4 · 21/8 - 31/2 : 15/4 + 56/9 · 9/23 - 121·100=
273/32 - 31/2 · 4/15 + 56/23 - 12100=
273/32 - 62/15 + 56/23 - 12100=
(273x345-62x736+56x480-12100x11040)/11040=
(94185-45632+26880-133584000)/11040
-133508567/11040 (sincer, nu-mi vine sa cred ca da un rezultat asa ''urat'' :)
