1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+117+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36=几
问题描述:
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+117+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36=几
答
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+117+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36
=(1+36)×36÷2
=666