Question

Bài 2a, 3145 - 246 + 2347 - 145 + 4246 - 347

Answer 1

3145 - 246 + 2347 - 145 + 4246 - 347

= (3145 - 145) + (4246 - 246) + (2347 - 347)

= 3000 + 4000 + 2000

= 9000

Answer 2

3145-246+2347-145+4246-347

=(3145-145)+(2347-347)+((-246)+4246)

=3000+2000+4000

=5000+4000

=9000