Question

15+15-15+15-15+15-15+15-15+15-15+15-15+15-15+15-15+16-16+17-20=?

Answer 1

 

 15+15-15+15-15+15-15+15-15+15-15+15-15+15-15+15-15+16-16+17-20

= 15+17-20 ( 15+15-15+15-15...+16-16 triệt tiêu đi còn 15+0 )

= 32-20

= 12

TÍCH CHO MÌNH NHA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 2

15+15-15+15-15+15-15+15-15+15-15+15-15+15-15+15-15+16-16+17-20=12