a) 25 × 34 × 4 = 25 × 4 × 34 = 100 × 34 = 3400

b) 128 × 93 + 128 × 7 = 128 × (93 + 7) = 128 × 100 = 12800

c) 57 × 63 - 47 × 63 = 63 × (57 – 47) = 63 × 10 = 630

57.63-47.63

=(57-47).63

=10.63

=630

63 nhân ( 57 trừ 47) =63 nhân 10 bằng 630

\(57\times63-47\times63\)

\(=63\times(57-47)\)

\(=63\times10\)

\(=630\)

a.25x34x4=25x4x34=100x34=340

b.128x93+128x7=128x(93+7)=128x100=12800\

c57x63-47x63=(57-47)x63=10x63=630

k cho mình nha

a, (25*4)*34=100*34=34000

b,  128*(93+7)=128*100=128000

c  63*(57-47)=63*10=630

Tính bằng cách thuận tiện:          

A) 25 x 34 x 4 = ( 25 x 4 ) x 34 = 100 x 3 = 3400           

B) 128 x 93 + 128 x 7 = 128 x ( 93 + 7 ) = 128 x 100 = 12800            

C) 57 x 63 - 47 x 63 = ( 57 - 47 ) x 63 = 10 x 63 = 630

= 5

5

`5/17 xx 21/4 xx 47/15 xx 0`

`= (5/17 xx 21/4) xx  (47/15 xx 0)`

`= (5/17 xx 21/4) xx 0`

`=0`

(36 × 27) : 3 = 36 × (27 : 3)

= 36 × 9

= 324

--------

(125 × 15) : 5

= 125 × (15 : 5)

= 125 × 3

= 375

--------

(15 × 12) : 9

= (5 × 3 × 12) : 9

= 5 × (36 : 9)

= 5 × 4

= 20

--------

450 : (3 × 5)

= 450 : 15

= 30

--------

(45 × 63) : 9

= 45 × (63 : 9)

= 45 × 7

= 40 × 7 + 5 × 7

= 280 + 35

= 315

a: \(\dfrac{\left(36\cdot27\right)}{3}=36\cdot\dfrac{27}{3}=36\cdot9=324\)

b: \(\dfrac{\left(125\cdot15\right)}{5}=125\cdot\dfrac{15}{5}=125\cdot3=375\)

c: \(\dfrac{\left(15\cdot12\right)}{9}=\dfrac{3\cdot3\cdot4\cdot5}{9}=4\cdot5=20\)

d: \(\dfrac{450}{3\cdot5}=\dfrac{450}{15}=30\)

e: \(\dfrac{45\cdot63}{9}=\dfrac{45}{9}\cdot63=63\cdot5=315\)