`-321+(-29)-142-(-72)`

`=-321-29-142+72`

`=-(321+29)-(142-72)`

`=-350-70`

`=-420`

-321 + (-29) - 142 - (-72)

=[(-321) + (-29)] - (142 + 72)

=       -350          -       214

= -564( cứ thấy sai sai:))

KQ = -420

\(-321+\left(-29\right)-142-a\left(-72\right)\)

\(=\left(-321-29-142\right)+72a\)

\(=-492+72a\)

a) -321  + (-29) - 142  - (-72)

= [-321  +(-29)]+ [(-142)  + 72]

= [-(321 + 29)] + [- (142 - 72)]

= (-350) + (-70)

= -(350 + 70)

= -420

b) 214 - (-36) + (-305)

= 214 + 36 - 305

= 250 - 305

= -(305 - 250)

= -55.

a, -321 + (-29 ) - 142 - (-72) = -321 - 29 - 142 + 72 = -420.

b, 214 - (-36) + (-305) = 214 + 36 - 305 = -55.

c, 232 - (581 + 132 - 331) = 232 - 581 - 132 + 331 = -150.

d, [ 12+ (-57)] - [-57 -  (-12) = 12 - 57 + 57 - 12 = 0.

a) \(-321+\left(-29\right)-142-\left(-72\right)\)

\(=-321-29-142+72\)

\(=-492+72\)

\(=-420\)

b) \(214-\left(-36\right)+\left(-305\right)\)

\(=214+36-305\)

\(=250-305\)

\(=-55\)

   \(\dfrac{3}{17}\) .\(\dfrac{6}{29}\) - \(\dfrac{3}{17}\).\(\dfrac{35}{29}\) + 2022\(\dfrac{3}{17}\)

= (\(\dfrac{3}{17}\).\(\dfrac{6}{29}\) - \(\dfrac{3}{17}\).\(\dfrac{35}{29}\)) + 2022 + \(\dfrac{3}{17}\)

= \(\dfrac{3}{17}\).(\(\dfrac{6}{29}\) - \(\dfrac{35}{29}\)) + 2022 + \(\dfrac{3}{17}\)

= \(\dfrac{3}{17}\).(-1) + 2022 + \(\dfrac{3}{17}\)

 = (- \(\dfrac{3}{17}\) + \(\dfrac{3}{17}\)) + 2022

= 0 + 2022

= 2022 

b; \(\dfrac{5}{6}\) - (\(\dfrac{1}{3}\) + \(\dfrac{1}{2}\)).20%

= \(\dfrac{5}{6}\) - \(\dfrac{5}{6}\).\(\dfrac{1}{5}\)

= \(\dfrac{5}{6}-\dfrac{1}{6}\)

= \(\dfrac{4}{6}\) 

= \(\dfrac{2}{3}\)

321 + 142 = 463

mình lớp 7 là con trai mặc quần lót đc chưa 

=463

k mk nha bn

mk k lại cho!

lấy nháp ra tính đi em !