1. 289*31+211*31 = 31(289+211) = 31*500 = 15500
2. 647*243-243*447 = 243(647-447) = 243*200 = 48600
3. 139*37-108*37 = 37(139-108) = 37*31 = 1147
4. 367*28+28*133 = 28(367+133) = 28*500 = 14000
5. 536*324-324*336 = 324(536-324) = 324*200 = 64800
6. 56*49+49*273 = 49(56+273) = 49*329 = 14147
7. 289*31+211*31 = 31(289+211) = 31*500 = 15500
8. 647*243-243*477 = 243(647-477) = 243*170 = 41310
9. 139*37-108*37 = 37(139-108) = 37*31 = 1147