2002+2004+2006+2008+2010+...+2050
=2000+2+2000+4+2000+6+2000+8+2000+10+...+2000+50
=2000X(50÷2)+(2+4+6+8+10+...+50)
=2000X25+25X26
=25X(2000+26)
=25X2026
=50650
2002+2004+2006+2008+2010+...+2050
=2000+2+2000+4+2000+6+2000+8+2000+10+...+2000+50
=2000X(50÷2)+(2+4+6+8+10+...+50)
=2000X25+25X26
=25X(2000+26)
=25X2026
=50650