Question

Tính nhanh

-(-800)+(1267-987)-(67-1987)

Answer 1

\(\text{-(-800)+(1267-987)-(67-1987)}\\ =800+1267-987-67+1987\\ =800+\left(1267-67\right)+\left(-987+1987\right)\\ =800+1200+1000\\ =3000\)

Answer 2

=800 +1267 -987 -67 + 1987

= 800 + (1267-67) +(1987 -987)

= 800 + 1200 + 1900

= (800+1200) +1900

= 2000+1900

=3900