a) 232 - (581 + 132 - 331)

= 232 - 581 - 132 + 331

= (232 - 132) - (581 - 331)

= 100 - 250

= -(250 - 100)

= -150

b) [12 + (-57)] - [-57 - (-12)]

= 12 - 57 + 57 - 12

= (12 - 12) + (57 - 57)

= 0 + 0

= 0

a: \(232-\left(581+132-331\right)\)

\(=232-581-132+331\)

\(=\left(232-132\right)+\left(-581+331\right)\)

\(=100-250\)

=-150

b: \(\left[12+\left(-57\right)\right]-\left[-57-\left(-12\right)\right]\)

\(=12+\left(-57\right)+57+\left(-12\right)\)

\(=\left(12-12\right)+\left(57-57\right)\)

=0+0

=0

a) \(232-\left(581+132-331\right)\)

\(=232-581-132+331\)

\(=\left(232-132\right)+\left(331-581\right)\)

\(=100-250\)

\(=-150\)

b) \(\left[12+\left(-57\right)\right]-\left[-57-\left(-12\right)\right]\)

\(=12-57+57-12\)

\(=\left(12-12\right)+\left(57-57\right)\)

\(=0+0\)

\(=0\)

a) 232 - ( 581 + 132 - 331 )

= 232 - 581 - 132 + 331

= ( 232 - 132 ) - ( 581 - 331 )

= 100 - 250

= -150

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, 232 - ( 581 + 132 -331)`

`= 232 - 581 - 132 +331`

`= (232-132) +(-581 + 331)`

`= 100 -250`

`=-150`

`b, [12+ (-57)] - [-57-(-12)]`

`= 12+ (-57) - (-57+12)`

`= 12+ (-57) + 57 -12`

`= (12-12) + (-57+57)`

`= 0+0`

`=0`

`a)232-(581+132-331)`

`=232-581-132+331`

`=(232-132)-(581-331)`

`=100-250`

`=-150`

`b)[12+(-57)]-[-57-(-12)]`

`=(12-57)-(-57+12)`

`=12-57+57-12`

`=(12-12)-(57-57)`

`=0-0`

`=0`

Bài 3.21:

b: =28+19-28-32+57

=76-32

=44

\(\frac{243^5.81^7.9^{15}.3^6.9^4.3^{18}}{9^8.729^8.81^9.27^5}=\frac{\left(3^5\right)^5.\left(3^4\right)^7.\left(3^2\right)^{15}.3^6.\left(3^2\right)^4.3^{18}}{\left(3^2\right)^8.\left(3^6\right)^8.\left(3^4\right)^9.\left(3^3\right)^5}=\frac{3^{25}.3^{28}.3^{30}.3^6.3^8.3^{18}}{3^{16}.3^{48}.3^{36}.3^{15}}=\frac{3^{115}}{3^{115}}=1\)

Ta có 

\(\frac{84}{-83}+1=-\frac{1}{83}=-\frac{6}{498}\)

\(-\frac{337}{331}+1=-\frac{6}{331}\)

Vì \(-\frac{6}{498}>-\frac{6}{331}\)

=> \(-\frac{84}{83}>-\frac{337}{331}\)

ta có\(\frac{237}{118}< \frac{354}{118}=3\)

\(3=\frac{993}{331}< \frac{994}{331}\)

vậy\(\frac{237}{118}< \frac{994}{331}\)

thấy hay thì tk mình nhe ^^