a) (12,1-11,9)/4+4,5 = 0.2 / 4 + 4.5 = 4.55
y=[(2,3+1,5)*12,5]/(2,05-1,25)
= (3.8 * 12.5) / 0.8)
= 47.5 / 0.8 = 59.375
ma = 31,9625
b) [(3,15+4,05)*36,9]/[(17,5-10,3)*0,41}
= (7.2 * 36.9) / (7.2*0.41)
= 265.68 / 2.952 = 90
y=21,7*(11,8-4,5) = 21,7 * 7,3 = 158.41
ma = 124,205