А) 23*8 9*23 184+207 391 51
= ------- + --------- = ---------------- = --------- = 4 ------ (или 4,6)
5*17 17*5 85 85 85
б) 716*6 6*284 4296-1704 2592 2
= ------------- - ------------- = ----------------------- = ---------- = 518 --- (или 518,4)
5 5 5 5 5