\(a,142\times12+142\times18=142\times\left(12+18\right)=142\times30=4260\\ b,49\times365-39\times365=365\times\left(49-39\right)=365\times10=3965\\ c,4\times18\times25=\left(4\times25\right)\times18=100\times18=1800\)

a) 142 x 12 + 142 x 18

=142x(12+18)

=142x30

=4260

b) 49 x 365 - 39 x 365

=(49-39)x365

=10x365

=3650

c) 4 x 18 x 25

=4x25x18

=100x18

=1800

a, =142. (12+18)

=142. 30

= 4260

b, = 365. (49-39)

= 365. 10

=3650

c,= 18. (25.4)

= 18. 100

=1800

Mình ghi dễ hiểu nhất rồi nha

Chúc bạn học tốt nha!

Bài 1:

a)345x200=69000           b)237x24=5688              c)403x346=139438

Bài 2:

a)95+11x206=2361       b)95x11+206=2361                  c)95x11x206=215270

1.

a) 69000; b) 5688; c) 139438

2.

a) 2361;b) 1251;c) 215270

3.

a) 2460

b) 3650

c) 1800

a) 142 x 12 + 142 x 18

= 142 x ( 18 + 12 )

= 142 x 30

= 4260

b) 49 . 365 - 39 . 365

= 365 . ( 49 - 39)

= 365 . 10

= 3650

c) 4 . 18 . 25

= 18 . 4 . 25

= 18 . 100

= 1800

a, 142 x 12 + 142 x18=142 x (12+18)= 4260

b, 49 x 365 - 39 x356 = 356 x (49-39)= 3560

c,4 x 18 x 25 = (25 x 4) x 18=1800

a,142 x 12 + 142 x 18 

=142 x (12+18)

=4260

b,49 x 365 - 39 x 365

= 365 x ( 49 -39 )

=365 x 10

=3650

c,4 x 18 x 25

=(4 x 25 ) x 18

= 100 x 18

= 1800

( 23 + 47) + (11 + 49) = 50 + 50 = 100

(4. 25) . (7 . 11) = 100 . 77 = 7700

23 + 47 + 11 + 49

=( 23 + 47 ) + (11+49)

= 70+60

=130

4.7.11.25

= (4.25) . (7.11)

=100 . 77

= 7700

k mình nha bn

\(23+47+11+49\)

\(=\left(23+47\right)+\left(11+49\right)\)

\(=70+60\)

\(=130\)

\(4.7.11.25\)

\(=\left(4.25\right).\left(7.11\right)\)

\(=100.77\)

\(=7700\)

23+47+11+49

=(23+47)+(11+49)

=    70    +   60

=          130

4.7.11.25

=(4.25).(7.11)

=  100 .  77

=     7700

5.9.3.2

=(5.2).(3.9)

=   10.  27

=     270

23+47+11+49 = 70 + 60 = 130

4.7.11.25 = 4 . 25 . 7 . 11 = 100 x 77 = 7700

5.9.3.2 = 5 x 2 x 3 x 2 = 10 x 6 = 60 

\(23+47+11+49\)

\(=\left(23+47\right)+\left(11+49\right)\)

\(=70+60\)

\(=130\)

\(4x7x11x25\)

\(=\left(4x25\right)x\left(7x11\right)\)

\(=100x77\)

\(=7700\)

\(5x9x3x2\)

\(=\left(5x2\right)x\left(9x3\right)\)

\(=10x27\)

\(=270\)

K mình nha mình nhanh nhất đó!

2x25x50xx8=(25x8)x(50x2)=200x100=20000

12x11+21x11+11x33=11x(12+21+33)=11x66=726

2*25*50*8

=(2*50)*(25*8)

=100*200=20000

12*11+21*11+11*33

=11*(12+21+33)

=11*66=676

2 x 25 x 50 x 8  = (8 x 25) x (50 x 2) = 200 x 100 = 20000

b) 12 x 11 + 21 x 11 + 11 x 13 = 11 x (12 + 21 + 33) 

= 11 x 66 = 726

a) 142 x 12 + 42 x 18

= 142 x (12 +18)

= 142 x 30 = 4260

b) 49 x 365 - 39 x 365

= (49   - 39) x 365

= 10 x 365 = 3650

c) 4 x 18 x 25

= 18 x (4 x 25)

= 18 x 100 = 1800

A) 142 x 12 + 142 x 18 

= 142 x ( 12 + 18 )

= 142 x 30 

= 4260 

B) 49 x 365 - 39 x 365 ;

= 365 x ( 49 - 39 )

= 365 x 10 

= 3650

C) 4 x 18 x 25

= 4x 25 x 18

= 100 x 18 

= 1800

a.142 x 12 +142 x 18 = 142 x ( 12 + 18 ) = 142 x 30 = 4260

b.49 x 365 - 39 x 365 = ( 49 - 39 ) x 365 = 10 x 365 = 3650

c.4 x 18 x 25 = ( 4 x 25 ) x 18 = 100 x 18 = 1800

hoc tot

a) 365.12.4+365.52=365.(12.4)+365.52=365.48+365.52=365.(48+52)=365.100=36 500

b)48.18+24.64=24.2.18+24.64=24.(2.18)+24.64=24.36+24.64=24.(36+64)=24.100=2 400

a)365x12x4+365x2

=365x48+365x2

=365(48+20

=365x50

=18250

b)48x18+24x64

=48x18+24x2x32

=48x18+48x32

=48x(18+32)

=48x50

=2400

2012 x 95 + 2012 x 4 + 2012

= 2012 x 95 + 2012 x 4 + 2012 x 1

= 2012 x ( 95 + 4 + 1 )

= 2012 x 100

= 201200

2012 x 95 + 2012 x 4 + 2012

= 2012 x 95 + 2012 x 4 + 2012 x 1

= 2012 x ( 95 + 4 + 1 )

= 2012 x 100

= 201200

\(2012\times95+2012\times4+2012\)

\(=2012\times\left(95+4+1\right)\)

\(=201200\)