Dễ mà , Khoa

4^5 - 8^3 + 2^6

=(2^2)^5 - (2^3)^3 + 2^6

=>2^10 - 2^9 + 2^6

=2^1+2^6

=2+64

=66

=> không chia hết cho 9

Chắc vậy

Mình thấy hơi khó nhìn một chút , bạn thông cảm nha

Ta có : 4⁵ - 8³ + 2⁶

= 1024 - 728 + 64

= 296 + 64 

= 360 

Mà 3 + 6 + 0 = 9 chia hết cho 9 => đpcm 

Vậy 4⁵ - 8³ + 2⁶ chia hết cho 9

Hok tốt

Ta có : 4⁵ - 8³ + 2⁶  = (2²)⁵ - (2³)³ + 2⁶

                               = 2¹⁰ - 2⁹ + 2⁶

                               = 1024 - 512 + 64

                               = 512 + 64

                               = 576

ta có : 576 chia hết cho 9 vì 576 = 5+7+6 = 18

mà 18 chia hết  cho 9

vậy  4⁵ - 8³ + 2⁶  chia hết cho 9

Do vai trò bình đẳng của x, y, z trong phương trình,

trước hết ta xét x ≤ y ≤ z.

Vì x, y, z nguyên dương nên xyz ≠ 0, do x ≤ y ≤ z

=> xyz = x + y + z ≤ 3z => xy ≤ 3=> xy thuộc {1 ; 2 ; 3}.

Nếu xy = 1 => x = y = 1,

thay vào (2) ta có : 2 + z = z, vô lí.

Nếu xy = 2, do x ≤ y nên x = 1 và y = 2,

thay vào (2), => z = 3.Nếu xy = 3,

do x ≤ y nên x = 1 và y = 3,

thay vào (2), => z = 2.

Vậy nghiệm nguyên dương của phương trình (2) là các hoán vị của (1 ; 2 ; 3)

phần kia thì chịu :)

1. We often go swimming in the summer, and they do, too.

2. She can speak English very well. I can, too.

3. Nam didn’t come to the party last night, and Minh didn’t, either.

4. Hoa will buy some oranges and pineapples. I will, too.

5. They don’t want to go out tonight, and we don’t, either.

6. The pineapples aren’t ripe, and the bananas ​aren’t, too.

7. Nam is hungry and his friends are, too.

8. Jane won’t come. Peter won’t, either.

9. Hoa had a medical check-up yesterday morning. We did, too.

10. He can’t swim and his brother can’t, either.

1. We often go swimming in the summer, and they..........do too.........

2.She can speak English very well. I..........can too....................

3.Nam didn’t come to the party last night, and Minh....didn't either....

4.Hoa will buy some oranges and pineapples. I....will too.....

5.They don’t want to go out tonight, and we.....don't either.....

6.The pineapples aren’t ripe, and the bananas..........aren't either....................

7.Nam is hungry and his friends........is too............................

8.Jane won’t come. Peter............won't either...........................

9.Hoa had a medical check-up yesterday morning. We......did too.........

10.He can’t swim and his brother........can't either..................................

1. We often go swimming in the summer, and they do, too.

2. She can speak English very well. I can, too.

3. Nam didn’t come to the party last night, and Minh didn’t, either.

4. Hoa will buy some oranges and pineapples. I will, too.

5. They don’t want to go out tonight, and we don’t, either.

6. The pineapples aren’t ripe, and the bananas aren’t, too.

TL:

A)   \(A=5+5^2+5^3+5^4+...+5^{49}+5^{50}\)

      \(5.A=5\left(5+5^2+5^3+5^4+...+5^{49}+5^{50}\right)\)

       \(5A=5^2+5^3+5^4+...+5^{50}+5^{51}\)

        \(5A-A=\left(5^2+5^3+5^4+...+5^{50}+5^{51}\right)-\left(5+5^2+5^3+5^4+...+5^{49}+5^{50}\right)\)

         \(4A=5^{51}-5\)

Vậy \(4A=5^{51}-5\left(đpcm\right)\)

B)      \(A=\left(5+5^2\right)+\left(5^3+5^4\right)+...+\left(5^{49}+5^{50}\right)\)

          \(A=5\left(1+5\right)+5^3\left(1+5\right)+...+5^{49}\left(1+5\right)\)

          \(A=5.6+5^3.6+...+5^{49}.6\)

           \(A=6.\left(5+5^3+...+5^{49}\right)⋮6\)

Vậy \(A\)chia hết cho 6 

HT!!~!