a) (580-40:2×4):25+550<600
(580-80):25+550<600
500:25+550<600
20+550<600
570<600 -ADEVĂRAT (A)
c) [(3+47+50):4+91]:2>50
(100:4+91):2>50
(25+91):2>50
116:2>50
58>50 -ADEVĂRAT (A)
b) 300-2×[5×(70-78:3)]:8>250
300-2×[5×(70-26)]:8>250
300-2×(5×44):8>250
300-2×220:8>250
300-55>250
245>250 -FALS (F)