a) 35 x 34 + 35 x 38 + 65 x 75 + 65 x 45

  = 35 x (34+38)  + 65 x (75 + 45)

  = 35 x 72   +    65 x 120

  =  2520 + 7800 = 10320

b)  3 x 25 x 8 + 4 x 37 x 6 + 2 x 38 x 12

 = 3 x ( 25 x 8) + 4 x (37 x 6) + 2 x (38 x 12)

 = 3 x 200 + 4 x 222 + 2 x 456

= 600 + 888 + 912 = 2400

tk nha

35 x 34 + 35 x 38 + 65 x 75 + 65 x 45 

= 35 x ( 34 + 38 ) + 65 x ( 45 + 75 )

= 35 x 72 + 65 x 120

Vì quy tắc thực hiện tính toán phải làm nhân chia trước nên :

= (35 x 34)+(35 x 38)+(65 x 75)+(65 x 45)

= (1190 + 1330) + (4875 + 2925)

= 2520 + 7800

=10320

b) (3 x 25 x 8) +( 4 x 37 x  6) + (2 x 38 x 12)

= 600 + 888 + 912

= 2400

b) 3.25.8+ 4.37.6+2.38.12

= 24.25+24.37+24.38

=24.(25+ 37+38)

=24.100

=2400

c) (563+745)-(463+545)

= (563-463)+(745+545)

=    100     +     100

=             200

bạn ơi cái phần c 745+545 = 1290 mà

a=10320

b=2400  

c=300

A = 78 x 31 + 78 x 24 + 78 x 17 + 22 x 72

A = 78 x ( 31 + 24 + 17 ) + 22 x 72

A = 78 x 72 + 22 x 72

A = 72 x ( 78 + 22 ) 

A = 72 x 100

A = 7200

C = 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21

C = 39 x ( 53 + 47 ) - 21 x ( 53 - 47 )

C = 39 x 100 - 21 x 6

C = 3900 - 126

C = 3774

ko pc tui thua bn 1 lp 

A = 78 x 31 + 78 x 24 + 78 x 17 + 22 x 72

A = 78 x ( 31 + 24 +17 ) + 22 x 72

A = 78 x 72 + 22 x 72

A = 72 x ( 78 + 22 )

A = 72 x 100

A = 7200

35 . 34 + 35 . 38 + 65 . 75 + 65 . 45 + 35 . 34 = 

= 35 . 34 + 35 . 38 + 35 . 34 + 65 . 75 + 65 . 45 

= 35 . ( 34 + 38 + 34 ) + 65 . ( 75 + 45 )

=  35 . 110  + 65 . 110 

= 110 . ( 35 + 65 ) 

= 110 . 100

= 11000

Hok tốt!!!!!!!!!!!!!

a) Tính bằng cách hợp lí nhất :

35 . 34 + 35 . 38 + 65 . 75 + 65 . 45 + 35 . 34

= 35 . 34 + 35 . 38 + 35 . 34 + 65 . 75 + 65 . 45

= 35 . ( 34 + 38 + 34 ) + 65 . ( 75 + 45 )

= 35 . 106 + 65 . 120

= 3710 + 7800

= 11510

3 . 25 . 8 + 4 . 37 . 6 + 2 . 38 . 12

= 3 . 8 . 25 + 4 . 6 . 37 + 2 . 12 . 38

= 24 . 25 + 24 . 37 + 24 . 38

= 24 . ( 25 + 37 + 38 )

= 24 . 100

= 2400

b) Tìm số tự nhiên x, biết :

( x - 5 ) ( x + 7 ) = 0

\(\Rightarrow\orbr{\begin{cases}x-5=0\\x+7=0\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-7\end{cases}}}.\)

Vậy .......

3 . 25 . 8 + 4 . 37 . 6 + 2 . 38 . 12 = 

= 3 . 8 . 25 +  4 . 6 . 37 + 2 . 12 . 38

= 24 . 25 + 24 . 37 + 24 . 38

= 24 . ( 25 + 37 + 38 )

= 24 . 100 

= 2400

Hok tốt!!!!!!!!!!!

a) 19 x 64 + 76 x 34 = 19 x 64 + 19 x 4 x 34 = 19 x (64 + 4 x 34) = 19 x 200 = 3800

b) 35 x 12 + 65 x 13 = 35 x 12 + 65 x 12 + 65 = 12 x (35 + 65) + 65 = 12 x 100 + 65 = 1265

c) 136 x 68 + 16 x 272 = 136 x 68 + 16 x 2 x 136 = 136 x (68 + 16 x 2) = 136 x 100 = 13600

cái này làm sao tính nhah đc

a) 19 x 64 + 76 x 34 = 19 x 64 + 19 x 4 x 34 = 19 x (64 + 4 x 34) = 19 x 200 = 3800

b) 35 x 12 + 65 x 13 = 35 x 12 + 65 x 12 + 65 = 12 x (35 + 65) + 65 = 12 x 100 + 65 = 1265

c) 136 x 68 + 16 x 272 = 136 x 68 + 16 x 2 x 136 = 136 x (68 + 16 x 2) = 136 x 100 = 13600

a)=35x(34+38)+72x(65+65)

=35x72+72x130

=72x(35+130)

=72x165

=11880

a) 3800

b) 1265

c) 13600

a) 19 . 64 + 76 .34 = 38. 32 + 38 . 68
                                  = 38 . (32 + 68) = 38 .100 = 3800
b) 35 . 12 + 65 . 13 = 35 . 12 + 65 . (12 + 1)
                                   = 35 . 12 + 65 . 12 + 65 = 12 . (35 + 65) + 65
                                   = 1200 + 65 = 1265.
c) 136 . 68 + 16 . 272 = 136 . 68 + 32 .136
                                       = 136 . (66 + 32) = 136 . 100 = 13600

k mik nha!

\(a,19\times64+76\times34.\)

\(=38\times32+38\times68\)

\(=38\times\left(68+32\right)\)

\(=38\times100\)

\(=3800\)

\(b,35\times12+65\times13\)

\(=35\times12+65\times\left(12+1\right)\)

\(=35\times12+65\times12+65\)

\(=12\times\left(35+65\right)+65\)

\(=12\times100+65\)

\(=1265\)

\(c,136\times68+16\times272\)

\(=136\times68+32\times136\)

\(=136\times\left(32+68\right)\)

\(=136\times100\)

\(=13600\)

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

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 x ( 34 + 38) + 65 x (40 + 32) = 35 x 72 + 65 x 72 = 72 x (35 + 65) = 72 x 100 = 7200

19 x 16 x 4 + 76 x 34

136 x 68 + 16 x2 x 136 

125 x 25 + 125 x 74 + 125