289*315+211*315 =315(289+211)=315*500=157500
647*243-243*447 =243(647-447)=243*200=48600
139*37-108*37+69*37 =37(139-108+69)=37*100=3700
1495*211+211*1505 =211(1495+1505)=211*3000=633000
3249*627-627*3049=627(3249-3049)=627*200=125400
289*315+211*315 =315(289+211)=315*500=157500
647*243-243*447 =243(647-447)=243*200=48600
139*37-108*37+69*37 =37(139-108+69)=37*100=3700
1495*211+211*1505 =211(1495+1505)=211*3000=633000
3249*627-627*3049=627(3249-3049)=627*200=125400
(647-447)×234=46800