308. Dacă: a = 20 + (100 - 8x8 - 4 x 2),
b = 50 - (65 - 3 x 6 + 1),
c = 2 + 27:9 + 21:7 - 2 x 1,
calculează:
a) a : (b + c)
b) 2 x a + 2 x b - 4xc;
c) 2 x a : (b + c) + a