Question

Tính nhanh?    2-3+4-5+6-7+8-9+10

Answer 1

mik lam theo cach tieu hoc nha!!!!!!!!

\(2-3+4-5+6-7+8-9+10=\left(2+4+6+8+10\right)-\left(3+5+7+9\right)\)

\(=30-24=6\)

neu dung thi ****

Answer 2

6                            

Answer 3

phan thanh phuong uyen bn chắc thông minh qá