a) 463+318+137+22

 = (463+137)+(318+22)

 =  600+340

 = 940

b) 185.32-32.85

 =  32.(185-85)

 =  32 . 100

 =  3200

c) \(15:\left\{390:\left[500-\left(125+35.7\right)\right]\right\}\)

\(\text{= }15:\left\{390:\left[500-\left(125+245\right)\right]\right\}\)

\(\text{= }15:\left\{390:\left[500-370\right]\right\}\)

\(=15:\left(390:130\right)\)

\(\text{= }15:3\)

\(\text{= }5\)

a)\(463+318+137+22\)

\(=\left(463+137\right)+\left(318+22\right)\)

\(=600+340=940\)

b)\(185.3^2-3^2.85\)

\(=3^2.\left(185-85\right)\)

\(=9.100=900\)

c)\(15:\left\{390:\left[500-\left(125+35.7\right)\right]\right\}\)

\(=15:\left\{390:\left[500-\left(125+245\right)\right]\right\}\)

\(=15:\left\{390:\left[500-370\right]\right\}\)

\(=15:\left\{390:130\right\}\)

\(=15:3=5\)

a) 463 + 318 + 137 + 22 = (463 + 137) + (318 +22) = 600 + 340 = 940

= 12 : {390 : [500 - (125 + 245)]}

= 12 : [390 : (500 - 370)]

= 12 : (390 : 130)

= 12 : 3

= 4

Số cần tìm là:

 4 

  Đ/S: 4

chúc bn học tốt

bằng  4 nha nhé các bạn

Đ/S : 4

k mk nha Huyền

12:{390:[500-(125+35.7)]}

=12:{390:[500-(125+245)]}

=12:{390:[500-370]}

=12:{390:130}

=12:3

=4

            \(12:\left\{390:\left[500-\left(125+35.7\right)\right]\right\}\)                        

      \(=12:\left\{390:\left[500-370\right]\right\}\)

      \(=12:\left[390:130\right]\)

      \(=12:3=4\)

kết quả là 3

12 : ( 390 : ( 500 - ( 125 +35 x 7 )

= 12 : (390 : (500 - (125 + 245) ) )

= 12 : (390 : ( 500 - 370 ) )

= 12 : ( 390 : 130 )

= 12 : 3

= 4 

\(12:\left(390:\left(500-\left(125+35\times7\right)\right)\right)\)

\(=12:\left(390:\left(500-370\right)\right)\)

\(=12:\left(390:130\right)\)

\(=12:3\)

\(=4\)

A = 12 : { 390 : [ 500 - ( 125 + 245 ) ] }

A = 12 : { 390 : [ 500 - 370 ] }

A = 12 : { 390 : 130 }

A = 12 : 3

A = 4

Ta có A = 12 : { 390 : [ 500 - 370 ]}

= 12 : { 390 : 130 }

= 12 : 3

= 4

12:(390:(500-(125+245)))

=12:(390:(500-370))

=12:(390:130)

=12:3

=4

12 : { 390 : [ 500 - ( 125 + 35 x 7 ) ] }

= 12 : { 390 : [ 500 - ( 125 + 245 ) ] }

= 12 : { 390 : [ 500 - 370 ) ] }

= 12 : { 390 : 130 }

= 12 : 3

= 4

Hok tốt

a: \(=28\cdot100=2800\)

\(24:\left\{390-[500-\left(125+35.7\right)]\right\}=2^x\)

\(24:\left\{390-[500-\left(125+245\right)]\right\}=2^x\)

\(24:\left\{390-[500-370]\right\}=2^x\)

\(24:\left\{390-130\right\}=2^x\)

\(24:260=2^x\)

Chỗ này sai đề ạ !

24 : { 390 - [ 500 - ( 125 + 35 . 7 ) ] } = 2^x

2^x = 24 : { 390 - [ 500 - ( 125 + 245 ) ] }

2^x = 24 : { 390 - [ 500 - 370 ] }

2^x = 24 : { 390 - 130 }

2^x = 24 : 260

2^x = 6/65 = ......................

=> Đề sai

12 : {390 : [500 - (125 + 35 . 7)]}

= 12 : {390 : [500 - (125 + 245)]}

= 12 : [390 : (500 - 370)]

= 12 : (390 : 130)

= 12 : 3

= 4

12 : { 390 : [ 500 - ( 125 + 35. 7 ) ] }

   =  12 : { 390 : [ 500 - ( 125 + 245 ) ] }

   =   12 : { 390 : [ 500 - 370 ] }

   =   12 : { 390 : 130 }

    =   12 : 3

    =     4