PO しl Let 4Let R be the reaion enclosed by oe en closed by Jhe graphs [sreph R ont omt y=8; x= o ind its avea.

9Sea Cutting nCA')-21, nCB)= 27, nCA'UB')= 36, NCANB)= 17 thhe using tor each reaion in the venn givon information to fill in the huuber of elements eliagram, A B The number of eleuehts in region x is メ The number of elerrents in egion y is - 80° Tue nuuber of elements in region Zis The number of elements in egion wis Sto S ope Ixenno TIMBUeD OITAUAESS 30 120°

5. Let (G, o) be a connected simple plane graph. Let F denote the set of faces in (G, o) and for fe F, (f) denote the length of f. Prove that Στενις (d(v) – 6) + 2Σ,cr((f) – 3) = -12. vEV(G) (Hint: Use Euler's Formula.)

3.