-84 : 4 + \(3^9:3^7+5^0=-21+3^2+1=-21+9+1=-11\)

= -11

= -21 + 9 + 1 

= -12 + 1

= -11

84:4 + 3⁹ : 3⁷ + 5⁰

= 21 + 3² + 1

= 21 + 9 + 1

= 30 + 1

= 31 

\(=21+3^2+1=22+9=31\)

\(=21+3^2+1=31\)

`@` `\text {Ans}`

`\downarrow`

`a)`

`84 \div 4 + 3^9 \div 3^7 + 5^0`

`= 21 + 3^2 + 1`

`= 21 + 9 + 1`

`= 30 + 1`

`= 31`

\(84:4+3^9:3^7+5^0=21+3^2+1=22+9=31\)

84 : 4 + 3⁹ : 3⁷ + 5⁰

= 84 : 4 + 3² + 1

= 84 : 4 + 9 + 1

= 21 + 9 + 1

= 30 + 1

= 31

Hướng dẫn giải:

a) 93 + 39 + 7 = (93 + 7) + 39 = 100 + 39 = 139.

89 + 85 + 11 = (89 + 11) + 85 = 100 + 85 = 185

184 + 66 + 16 = (184 + 16) + 66 = 200 + 66 = 266

b) 23 + 52 + 47 + 98 = (23 + 47) + (52 + 98) = 70 + 150 = 220

16 + 490 + 84 + 10 = (16 + 84) + (490 + 10) = 100 + 500 = 600 

ta có 50^40>50^39

        50^39>50^38=)1/50^39<1/50^38

=)50^40+1/50^39>50^39+1/50^38

=)50^40+1/50^39+1>50^39+1/50^38+1

=)A>B

1: =-3x5+2x5-7x5+7x4=-8x5+7x4=-40+28=-12

2: =-3x5+3x6-4x3+4x2=-9+8=-1

3: =17(-84-16)=-1700

4: =1975(-115+15)=-197500

5: =-145x13+145x57+57x10-57x145=-1315

1/ \(5\left(-3+2\right)-7\left(5-4\right)\)

\(=5.\left(-3\right)+5.2-7.5-7.\left(-4\right)\)

\(=-15+10-35+28\)

\(=-5-7\)

\(=-12\)

2/ \(3.\left(-5+6\right)-4.\left(3-2\right)\)

\(=3.\left(-5\right)+3.6-4.3-4.\left(-2\right)\)

\(=-15+18-12+8\)

\(=3-4\)

\(=-1\)

3/ \(17.\left(-84\right)+17.\left(-16\right)\)

\(=17.\left(-84-16\right)\)

\(=17.\left(-100\right)\)

\(=-1700\)

4/ \(1975.\left(-115\right)+1975.15\)

\(=1975.\left(-115+15\right)\)

\(=1975.\left(-100\right)\)

\(=-197500\)

5/ \(-145.\left(13-57\right)+57.\left(10-145\right)\)

\(=-145.13-145.\left(-57\right)+57.10+57.\left(-145\right)\)

\(=-145.\left(-57+57\right)-145.13+57.10\)

\(=0-1885+570\)

\(=-1315\)

6/ \(157.17-157.7\)

\(=157.\left(17-7\right)\)

\(=157.10\)

\(=1570\)

7/ \(199.\left(15-17\right)-199.\left(-17+5\right)\)

\(=199.\left(-2\right)-199.\left(-12\right)\)

\(=199.\left(-2\right)+199.12\)

\(=199.\left(-2+12\right)\)

\(=199.10\)

\(=1990\)

8/ \(-39.\left(5-99\right)+99.\left(10-39\right)\)

\(=-39.5-39.\left(-99\right)+99.10+99.\left(-39\right)\)

\(=-39.\left(-99+99\right)-39.5+99.10\)

\(=0-195+990\)

\(=795\)

9/ \(-38.\left(25-4\right)+25.\left(-4+38\right)\)

\(=-38.25-38.\left(-4\right)+25.\left(-4\right)+25.38\)

\(=25.\left(-38+38\right)-4.\left(-38+25\right)\)

\(=0-4.\left(-13\right)\)

\(=52\)

10/ \(\left(-37\right).86+37.76\)

\(=37.\left(-86\right)+37.76\)

\(=37.\left(-86+76\right)\)

\(=37.\left(-10\right)\)

\(=-370\)

Phương pháp giải:

Cộng các số rồi điền kết quả vào chỗ trống.

Lời giải chi tiết:

6 + 7 = 13        7 + 8 = 15

8 + 9 = 17        17 + 6 = 23

28 + 7 = 35      39 + 8 = 47

30 + 4 = 34      60 + 6 = 66

8 + 50 = 58      5 + 16 = 21

4 + 27 = 31      5 + 38 = 43

a: \(3^8:3^4+2^2\cdot2^3\)

=81+32

=123

b: \(3\cdot4^2-2\cdot3^2\)

\(=48-18\)

=30

a, 3⁸: 3⁴+ 2². 2³

= 3^8-4 + 2²⁺³

= 3⁴ + 2⁵

= 81 + 32

= 113

b,  3 . 4²- 2 . 3²

= 3 . 16 - 2 . 9

= 48 - 18

= 30

c,  84 : 4 + 3⁹: 3⁷+ 5⁰

= 84 : 4 + 3² + 1

= 84 : 4 + 9 + 1

= 21 + 9 + 1

= 31

d,  295 - ( 31 - 2² . 5)²

= 295 - ( 31 - 4 . 5 )²

= 295 - ( 31 - 20 )²

= 295 - 11²

= 295 - 121

= 174

e, 500 - {5[409 - (2³ . 3 - 21)² ] + 10³ } : 15

= 500 -  {5[409 - (8 . 3 - 21)² ] + 10³ } : 15

= 500 -  {5[409 - (24 - 21)² ] + 10³ } : 15

= 500 -  {5[409 - 3² ]+ 10³ } : 15

= 500 - {5[409 - 9 ]+ 10³ } : 15

= 500 - {5 . 400 + 1000 } : 15

= 500 - {2000 + 1000} : 15

= 500 - 3000 : 15

= 500 - 200

= 300

g, 5³ . 2 - 100 : 4 + 2³ . 5

= 125 . 2 - 100 : 4 + 8 . 5

= 250 - 25 + 40

= 225 + 40

= 265

h, 205 - [1200 - (4² - 2 . 3)³ ] : 40

= 205 - [ 1200 - ( 16 - 2 . 3 )³ : 40

= 205 - [ 1200 - ( 16 - 6 )³  ] : 40

= 205 - [ 1200 - 10³ ] : 40

= 205 - [ 1200 - 1000 ] : 40

= 205 - 200 : 40

= 205 - 5

= 200

Đây nha bạn!!!

157*(17-7)=......

(-37)*86 - (-37)*76=(-37)*(86-76)=.......

1975*(-115+15)=....

199*[(15-17)-(-17+5)]=........

17*[-84+(-16)]=.......