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

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

= 35 x     72      + 65 x (75+45)

= 35 x 72 + 65 x 120

= 35 x 72 + 65 x (72 + 48)

= 35 x 72 + 65 x 72 + 65 x 48

= (35+65) x 72 + 65  x 48

=   100 x 72 + 65 x 48

=      7200   +    3120

=           10320

b.39 x 8 + 60 x 2 + 21 x 8

=39 x 8 + 15 x 4 x 2 +21 x 8

= 39 x 8 + 15 x 8 + 21 x 8

=(39 + 15 + 21) x 8

=      75            x 8

=             600

c.58 x 75 + 58 x 50 - 58 + 25

= 58 x 75 + 58 x 50 - 58 x 1 + 25

= 58 x(75+50-1)+25

= 58 x   124     + 25

=    7192          + 25

=              7217

d.125 x 98 - 125 x 46 - 52 x 25

= 25 x 5 x 98 - 25 x 5 x 46 - 25 x 52

= 25 x 490 - 25 x 230 - 25 x 52

= 25 x (490 - 230 - 52)

= 25 x      208

=       5200

ham mo chi qua

a. 64 x 25 + 35 x 25 + 25

= 64 x 25 + 35 x 25 + 25 x 1

= 25 x ( 64 + 35 + 1 )

= 25 x 100 

= 2500

b. 58 x 42 + 32 x 8 + 5 x 16

c. ( 42 x 43 + 57 x 43 + 43 ) - 360 : 4

= 42 x 43 + 57 x 43 + 43 x 1 - 90

= 43 x ( 42 + 57 +1 ) - 90

= 43 x 100 - 90

= 4300 - 90

= 4210

d. 456 : 2 x 181456 : 3 - 102

Trả lời:

a,\(64\times25+35\times25+25\)

\(=25\times\left(64+35+1\right)\)

\(=25\times100\)

\(=2500\)

b,\(58\times42+32\times8+5\times16\)

\(=2436+256+80\)

\(=2772\)

c,\(\left(42\times43+57\times43+43\right)-360\div4\)

\(=43\times\left(42+57+1\right)-90\)

\(=43\times100-90\)

\(=4300-90\)

\(=4210\)

d,\(456\div2\times181456\div3-102\)

\(=228\div3\times181456-102\)

\(=76\times181456-102\)

\(=13790656-102\)

\(=13790554\)

a,64 x 25 + 35 x 25 +25

=25x(64+35+1)

=25x100

=250

b, 58 x 42 +32 x 8 +5 x 16

=2772

c,(42 x 43 +57 x 43+43 )-360:4

=43x(42+57+1) - 360 :4

= 43 x 100 -90

=4300-90

=4210

d,456:2 x 181456:3 -102

=228x181456:3-102

=13790656-102

=13790554

a)64x25+35x25+25=25x(64+35)+25=25x99+25=2475+25=2500

mình trả lời ý a

64 x 25 +35 x 25 +25 x 1

= 25 x ( 64 + 35 + 1 )
= 25 x 100

= 2500

Tính nhanh:

a) 64 x 25 + 35 x 25 + 25 

= 64 x 25 + 35 x 25 + 25 x 1

= 25 x ( 64 + 35 + 1 )

= 25 x 100

= 2500

  b) 58 x 42 + 32 x 8 + 5 x 16

= 

25 x 34 + 65 x 75 - 35 x 86 + 65 x 45

= 5 x 17 x 10 + 65 x (75 + 45) - 7 x 43 x 10

= 85 x 10 + 780 x 10 - 301 x 10

= 10 x (85 + 780 - 301)

= 10 x 564

= 5640

4a) \(\frac{x}{36}=\frac{3}{4}\)

\(\Rightarrow\frac{x}{36}=\frac{27}{36}\)

\(\Rightarrow x=27\)

4b) 33 + x = 71 - 26

33 + x = 45

x = 45 - 33

x = 12

4c) x * (3,5 + 1,5) = 10

x * 5 = 10

x = 10 ; 5 = 2

4,

\(a,\frac{x}{36}=\frac{24}{32}\)

\(=>\frac{x}{36}=\frac{3}{4}=\frac{27}{36}\)

\(=>x=27\)

\(b,71-\left(33+x\right)=26\)

\(=>-\left(33+x\right)=26-71=-45\)

\(=>33+x=45\)

\(=>x=12\)

\(c,3,5\cdot x+1,5\cdot x=10\)

\(>x\cdot\left(3,5+1,5\right)=10\)

\(=>x\cdot5=10\)

\(=>x=2\)

. là nhân nha

4. 

a) x/36 = 24/32

24/32 = 3/4 = 27/36

=> x = 27

b) 71 - ( 33 + x ) = 26

33 + x = 71 - 26

33 + x = 45

x = 45 - 33

x = 12

c) 3, 5 . X + 1, 5 . x = 10

x( 3, 5 + 1, 5 ) = 10

x . 5 = 10

x = 10 : 5

x = 2

5.

a) 4, 63 . 7, 8 + 7, 8 + 7, 8 . 4, 32

= 7, 8. ( 4, 63 + 4, 32 + 1 )

= 7, 8 . 9, 95

= 77, 61

b) 35 . 34 + 35 . 86 + 65 . 75 + 65 . 45

= 35( 34 + 86 ) + 65( 75 . 45 )

= 35 . 120 + 65 . 120

= 120 . ( 35 + 65 )

= 120 . 100

= 12 000

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) 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