3,2 + 4,65 : 1,5 

=3,2+3,1

=6,3

347 + 418 + 123 + 12

=(347+123)+(418+12)

=470+430

=900

34 x 35 + 35 x 38 + 65 x 40 + 65 x 32

=35*(34+38)+65*(32+40)

=35*72+65*72

=72*(35+65)

=72*100

=7200

19 x 16 x 4 + 76 x 34

=76*16+76*34

=76*(16+34)

=76*50

=3800

136 x 68 + 16 x2 x 136 

=136*68+32*136

=136*(68+32)

=136*100

=13600

125 x 25 + 125 x 74 + 125

=125*(25+74+1)

=125*100

=12500

Tính bằng cách thuận tiện hả

A=[(38+17)+125]+29

A=175+29

A=204

B=312.3

B=936

C=1+1+1+1+1

C=5

D=(125:5).(36:9)

D=25.4

D=100

\(-136\cdot(64-95)-64\cdot(-95-136)\\=-136\cdot64+(-136)\cdot(-95)+(-64)\cdot(-95)+(-64)\cdot(-136)\\=-136\cdot64+136\cdot95+64\cdot95+64\cdot136\\=(-136\cdot64+64\cdot136)+(136\cdot95+64\cdot95)\\=0+95\cdot(136+64)\\=95\cdot200\\=19000\)

\(136.\left(143+157\right)+157.64+143.64\)

\(=136.300+157.64+143.64\)

\(=136.300+64.\left(157+143\right)\)

\(=136.300+64.300\)

\(=300.\left(136+64\right)\)

\(=300.200\)

\(=60000\)

Thế này mới đúng :

136 . ( 143 + 157 ) + 157 . 64 + 143 . 64

= 136 .  300   + ( 157 + 143 ) . 64

=       40800     +       300  . 64 

=                 40800 +  19200

=                       60000

a) \(437\times136-437\times125\)

\(=437\times\left(136-125\right)\)

\(=437\times11\)

\(=4807\)

b) \(2009\times71+29\times2009\)

\(=2009\times\left(71+29\right)\)

\(=2009\times100\)

\(=200900\)

a) 437 x 136 - 437 x 125

= 437 x (136 - 125 )

= 437 x 11

=  4807

b) 2009 x 71 + 29 x 2009

= 2009 x ( 71 + 29 ) 

= 2009 x 100

= 200900

140x134>136x136

=140x134=(136+4)x(136-2)=136x136-2x136+4x136-8=136x136+2x136-8>136x136

a) 16635

b)7x=49 x=7

c)125(y+z)=125

y+z=1

cậu cho tớ cách giải đi

4177

13400

3400

5200

4000

4177

13400

3400

5200

4000

a. \(678\times\left(276+49\right)-678\times\left(149+76\right)\)

\(=678\times\left[\left(276+49\right)-\left(149+76\right)\right]\)

\(=678\times\left(276+49-149-76\right)\)

\(=678\times\left(200-100\right)\)

\(=67800\)

b. \(23\times157+15\times46-28\times87\)

\(=3611+690-2436\)

\(=1865\)

c. \(12:\left\{390:\left[500-\left(125+35\times7\right)\right]\right\}\)

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

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

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

\(=12:3\)

\(=4\)