Question

Tính nhanh: 199-200+201-202+203-204+205-206+207

Answer 1

199 - 200 + 201 - 202 + 203 - 204 + 205 - 206 + 207

= ( 199 - 200 ) + ( 201 - 202 ) + ( 203 - 204 ) + ( 205 - 206 ) + 207

= ( -1 ) + ( -1 ) + ( -1 ) + ( -1 ) + 207

= -4 + 207

= 203

Answer 2

199 - 200 + 201 - 202 + 203 - 204 + 205 - 206 + 207 = 203 

Answer 3

199-200+201-202+203-204+205-206+207

=203