Tính

Di Tinkgo te behe
a) (33,7-39,5), (57,6-59,4)
b) (85,5+4,5)-(12,027 7,98)
c) (15,25+ 3,75), 4+ (20,7 4+ 5, 299: 5
d) (34,72+ 32,28): 5-(57, 25-36,05): 2