a , 23(34+56) = 23* 90 = 2070

b , 33(409 + 124) = 33 * 633

34 x 23 + 56 x 23 = 23 x (34 + 56) = 23 x 90 = 2070

409 x 34 + 124 x 34 = 34 x (409 + 124) = 34 x 533 = 18122

24x23+56x23=23x(34+56=23=100=2300

409x34+124+34=34x(409+124)=34x533=12792

1.Tính nhanh nếu có thể:
a) 22 + 23 + 89 + 77
= ( 77 + 23 ) + 22 + 89
= 100 + 22 + 89
= 122 + 89
= 211
b) 35 . 15 + 15 . 65
= 15 . ( 35 + 65 )
= 15 . 100
= 1500
c) 7^2 - 36 : 3^2
=  7^2 - 36 : 9
= 7^2 - 4
= 49 - 4
= 45
d) 476 - {5 . [409 - (8 . 3 - 21)2] - 1724}
= 476 - {5 . [409 - (24 - 21)^2] - 1724}
= 476 - {5 . [409 - (3^2)] -  1724}
= 476 - {5 . [409 - 9 ] - 1724}
= 476 - {5. 400 - 1724}
= 476 - {2000 - 1724}
= 476 - 276
= 200

2. Tìm x, biết:

a) x + 37 = 50

x = 50 - 37

x = 13

b) 2x - 3 = 11

2x = 11 + 3

2x = 14

2x = 2 . 7

    \(500-\left\{5\left[409-\left(2^3\cdot3-21\right)^2+10^3\right]\right\}:15\)
\(=500-\left\{5\left[409-9+1000\right]\right\}:15\)
\(=500-\left\{5\cdot1400\right\}:15\)
\(=500-7000:15\)
\(=500-\dfrac{1400}{3}\)
\(=\dfrac{100}{3}\)



    \(67-\left[8+7\cdot3^2-24:6+\left(9-7\right)^2\right]:15\)
\(=67-\left[8+7\cdot9-24:6+4\right]:15\)
\(=67-\left[8+63-4+4\right]:15\)
\(=67-71:15\)
\(=67-\dfrac{71}{15}\)
\(=\dfrac{934}{15}\)

\(PeaGea\)

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!!!

500 - {5.[409.(2³.3 - 21)²] + 10³ } : 15

= 500 - { 5. [409.(8.3 - 21)² ] + 1000} : 15

= 500 - {5. [409.(24 - 21)² ] + 1000} : 15

= 500 - {5. [409.3² ] + 1000} : 15

= 500 - {5. [409.9] + 1000} : 15

= 500 - {5. 3681 + 1000} : 15

= 500 - {18405 + 1000} : 15

= 500 - 19405 : 15

= 500 - 1293,66666666....

= Không có số thỏa mãn đề bài.

Anh ơi chỗ 409 là trừ - em nhầm

Em đăng lại câu hỏi đi

a 2

b 5

9187 - x : 409 = 7819

x : 409 = 9187 - 7819

x : 409 = 1368

x = 1368 * 409

x = 559512