Răspuns :
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[tex]\it 23710+23740+23750+23760+23780+23790=[/tex]
[tex]\it =23700+10+23700+40+23700+50+23700+60+23700+80+23700+90\\ \\\\=23700\cdot6+10(1+4+5+6+8+9) = 142200+330=142530[/tex]
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[tex]\it 23710+23740+23750+23760+23780+23790=[/tex]
[tex]\it =23700+10+23700+40+23700+50+23700+60+23700+80+23700+90\\ \\\\=23700\cdot6+10(1+4+5+6+8+9) = 142200+330=142530[/tex]