Question

[bảo chiến phi long]

​tính nhanh

4,5*3*780+1304*13,5 

3+6+9+12+15+18+21+24+27

Answer 1

[Hàn Tuyết Ly]

cau 1 sai de

cau 2 :

3+6+9+12+15+18+21+24+27= (3+27)+(6+34)+(9+21)+(12+18)+15= 30+30+30+30+15=135