Question

-87+(-12)-(-487)+512

(18+29)+(158-18-29)

Answer 1

900

158

Answer 2

\(\text{-87+(-12)-(-487)+512}\\ =\left(-87-\left(-487\right)\right)+\left(-12\right)+512\\ =400+500\\ =900\)

Answer 3

Bài 1:

= - 87 - 12 + 487 + 512

= ( 487 - 87 ) + ( 512 - 12 )

= 400 + 500 = 900

Bài 2:

= 18 + 29 + 158 - 18  - 29

= ( 18 - 18 ) + ( 29 - 29 ) + 158

= 158

Answer 4

(-87) + (-12) - (-487) + 512
= (-87) + (-12) + 487 + 512
= [512 + (-12)] + [487 + (-87)]
= 500 + 400
= 900
(18 + 29) + (158 - 18 - 29)
= 18 + 29 + 158 - 18 - 29
= 18 + 29 + 158 + (-18) + (-29)
= [18 + (-18)] + [29 + (-29)] + 158
= 0 + 0 + 158
= 158