Question

11+12.+29怎么算,还有1+2.+50怎么算

Answer 1

(11+29)+(12+28)+(13+27)+(14+26)+(15+25)+(16+24)+(17+23)+(18+22)+(19+21)+20

=40+40+40+40+40+40+40+40+40+20

=380

(1+49)+(2+48)+(3+47)+(4+46)+(5+45)+(6+44)+(7+43)+(8+42)+().+50

=50*25+50

=1300