a) 25 601 ; 25 602 ; 25 603 ; 25 604 ; 25 605 ; 25 606 ; 25 607.

b) 89 715 ; 89 716 ; 89 717 ; 89 718 ; 89 719 ; 89 720 ; 89 721.

c) 28 000 ; 29 000 ; 30 000 ; 31 000 ; 32 000 ; 33 000.

d) 54 400 ; 54 500 ; 54 600 ; 54 700 ; 54 800 ; 54 900.

23/25=0,92

78/50=1,56

34/25=1,36

89/50=1,78

2476 k đi

2476 nha bạn k đi

a) 23 + 25 + 27 + 29 + 31 + 33 + 35

= 23 + ( 25 + 35 ) + ( 27 + 33 ) + ( 29 + 31 )

= 23 +        60      +      60         +      60

= 23 + 60 x 3

= 23 +    180

= 203

b) 4 . 36 . 25 . 50

=  4 . 4 .9 . 25 . 25 . 2

= 4 . 25 . 4 . 25 . 9 . 2

=   100 . 100     . 9 . 2

= 10 000           . 18

= 180 000

c) 32 . 125 . 3 

= 4 . 8 . 5 . 25 . 3

= 4 . 25 . 8 . 5 . 3

=  100    . 8 . 5 . 3

=      800 . 5 . 3

= 4000 . 3

= 12000

d, 36 . 19 + 36 . 81

= 36 . ( 19 + 81 )

= 36 . 100

= 3600

e, 78 . 31 + 78 . 24 + 78 . 17 + 22 x 72

= 78 . ( 31 + 24  + 17 ) + 22 x 72

= 78 . 72 + 22 . 72

= 72 . ( 78 + 22 )

= 72 . 100

= 7200

A)23+25+27+29+31+33+35

= (33+27)+(25+35)+(29+31)+23

=60+60+60+23

=60x3+23

=180+23

=203

B)4.36.25.50=(36.25).(4.50)

=(4.9.25).(2.2.50)

=(4.25).9 .(2.50).2

=100.9.100.2

=100.(9+2)

=100 .11

=1100

C)32.125.3=(4.8).125.3

=(125.8).(4.3)

=1000.12

=12000

D)36.19.36.81=36.(19+81)

 = 36.100

=3600

E)78.31.+78.24+78.17+22x72=78.31+78.24+78.17+ (16+6).72

=78.31+78.24+78.17+78.16

=78.(31+24+17+16)

=78.88

=6864

11: \(=215\cdot\left(-14+1236\right)+215\cdot\left(14-236\right)\)

\(=215\left(-14+1236+14-236\right)=215\cdot1000=215000\)

12: \(=125\cdot25-125\cdot89+128\cdot89-128\cdot125\)

\(=125\cdot\left(-103\right)+89\cdot3\)

=-12608

\(89x+25x-14x=4500\\ =>x\left(89+25-14\right)=4500\\ =>100x=4500\\ =>x=4500:100\\ =>x=45\)

tất cả là 1

bằng1

a) 89 + 10 x 2 = 89 + 20

                   = 109

b) 25 x 2 + 78 = 50 + 78

                   = 128

c) 46 + 77 x 2 = 46 + 14

                   = 60

d) 35 x 2 + 90 = 70 + 90

                   = 160