cha mi hỏi ngu như cho

chết đi cho rồi, chó nhà tau cx trả lời đc

B = 3+3³ +3⁵ +…+3²⁰¹¹ +3²⁰¹³

3² B = 3³ +3⁵ +3⁷ +…+3²⁰¹³ +3²⁰¹⁵

3² B-3B =(3³ +3⁵ +3⁷ +…+3²⁰¹³ +3²⁰¹⁵) – (3+3³ +3⁵ +…+3²⁰¹¹ +3²⁰¹³)

8B =3²⁰¹⁵- 3 ( bỏ ngoặc rồi rút gọn)

Suy ra 8 B +3 = 3²⁰¹⁵, là một luỹ thừa

1.
a) \(3^4\times3^5\times3^6=3^{4+5+6}=3^{15}\)

b) \(5^2\times5^4\times5^5\times25=5^2\times5^4\times5^5\times5^2=5^{2+4+5+2}=5^{13}\)

c) \(10^8\div10^3=10^{8-3}=10^5\)

d) \(a^7\div a^2=a^{7-2}=a^5\)

2.

\(987=900+80+7\\ =9\times100+8\times10+7\\ =9\times10^2+8\times10^1+7\times10^0\)

\(2021=2000+20+1\\ =2\times1000+2\times10+1\times1\\ =2\times10^3+2\times10^1+1\times10^0\)

\(abcde=a\times10000+b\times1000+c\times100+d\times10+e\times1\\ =a\times10^4+b\times10^3+c\times10^2+d\times10^1+e\times10^0\)

còn bài 2

Bài 1

a) 3⁴ + 3⁵ + 3⁶ + 3⁷ = 3⁴(1 + 3 + 3² + 3³)\

b) a)A = 1 + 3 + 3² +......3⁹⁹ =(1 + 3 +  3² + 3³ ) + ...+(3⁹⁶ + 3⁹⁷ + 3⁹⁸ + 3⁹⁹)

                                          =   (1 + 3 +  3² + 3³ ) + .. +3⁹⁶(1 + 3 +  3² + 3³ )

                                          = 40 + ... + 3⁹⁶ . 40 

                                          = 40 (1 + 3 +...+ 3⁹⁶) chia hết cho 40

Bài 2 

a)

+)A chia hết cho 6

\(A=5+5^2+5^3+...+5^{2004}\)

\(A=\left(5+5^2\right)+\left(5^3+5^4\right)+...+\left(5^{2003}+5^{2004}\right)\)

\(A=\left(5+5^2\right)+5^2\left(5+5^2\right)+...+5^{2002}\left(5+5^2\right)\)

\(A=30+5^2.30+...+5^{2002}.30\)

\(A=30\left(1+5^2+...+5^{2002}\right)\)chia hết cho 6

+)A chia hết cho 31

\(A=5+5^2+5^3+...+5^{2004}\)

\(A=\left(5+5^2+5^3\right)+\left(5^4+5^5+5^6\right)+...+\left(5^{2002}+5^{2003}+5^{2004}\right)\)

\(A=\left(5+5^2+5^3\right)+5^3\left(5+5^2+5^3\right)+...+5^{2001}\left(5+5^2+5^3\right)\)

\(A=155+5^3.155+...+5^{2001}.155\)

\(A=155\left(1+5^3+...+5^{2001}\right)\)chia hết cho 31

+) A chia hết cho 156

\(A=5+5^2+5^3+...+5^{2004}\)

\(A=\left(5+5^2+5^3+5^4\right)+\left(5^5+5^6+5^7+5^8\right)+...+\left(5^{2001}+5^{2002}+5^{2003}+5^{2004}\right)\)

\(A=\left(5+5^2+5^3+5^4\right)+5^4\left(5+5^2+5^3+5^4\right)+...+5^{2000}\left(5+5^2+5^3+5^4\right)\)

\(A=780+5^4.780+...+5^{2000}.780\)

\(A=780\left(1+5^4+...+5^{2000}\right)\)chia hết cho 156

b)B=165+2^15 chia hết cho 33

ta có 165 chia hết cho 33

mà 2¹⁵ ko chia hết cho 33

vậy 165+2^15 không chia hết cho 33 hay B không chia hết cho 33.

chứng tỏ A= 1+\(3^1\)+\(3^2\)+....+\(3^{99}\)là B(4) và là B (40).

Câu 3 :

A = 7776 . 8 - 2.243. 64

A = 62208 - 31104

A = 31104

Câu 1 :

a) \(12^5=3^5.4^5\)

b) \(20^6=4^6.5^6\)

c) \(54^3=6^3.9^3\)

Câu 2 :

a) \(3.5^{55}=3.\left(5^5\right)^{11}\)

b) \(4.3^{816}=4.\left(3^{17}\right)^{48}\)

c) \(9.8.7^{6412}=9.8.\left(7^{28}\right)^{229}\)

\(a,3^7.27^5.81^3\\ =3^7.\left(3^3\right)^5.\left(3^4\right)^3\\ =3^7.3^{15}.3^{12}\\ =3^{34}\\ b,100^6.1000^5.10000^4\\ =100^6.100^{10}.100^{12}\\ =100^{28}\\ c,125^4:5^8\\ =5^{12}:5^8\\ =5^4.\)

a) \(\left(-5\right)\left(-5\right)\left(-5\right)\left(-5\right)\left(-5\right)=\left(-5\right)^5\)

b)\(\left(-2\right)\left(-2\right)\left(-2\right)\left(-3\right)\left(-3\right)\left(+3\right)=\left(-2\right)^3\cdot\left(-3\right)^2\cdot3=\left(-2\right)^3\cdot3^3\)

c) \(\left(-7\right)\cdot7\cdot5\cdot\left(-5\right)\left(-5\right)=\left(-7^2\right)\cdot\left(-5\right)^3\)

d) \(\left(-8\right)\left(-3\right)3\cdot125=\left(-2^3\right)\cdot\left(-3^2\right)\cdot5^3\)

e) \(27\cdot\left(-2\right)3\left(-7\right)\cdot49=3^4\cdot\left(-2\right)\cdot\left(-7^3\right)\)

a: \(\left(-5\right)\cdot\left(-5\right)\cdot\left(-5\right)\cdot\left(-5\right)\cdot\left(-5\right)=\left(-5\right)^5\)

b: \(\left(-2\right)\cdot\left(-2\right)\cdot\left(-2\right)\cdot\left(-3\right)\cdot\left(-3\right)\cdot\left(+3\right)=\left(-2\right)^3\cdot3^3\)

25^6.125^8=5^12.5^24=5^36

cấp hai rồi vẫn còn viết dấu x

a) 3³ . 3⁴ = 3⁷

b) 5² . 5⁷ = 5⁹

c) 7⁵ . 7 = 7⁶

a) \(3^3.3^4=3^{3+4}=3^7\)

b) \(5^2.5^7=5^{2+7}=5^9\)

c) \(7^5.7=7^{5+1}=7^6\)

\(3^3.3^4=3^{3+4}=3^7\)

\(5^2.5^7=5^{2+7}=5^9\)

\(7^5+7=7^{5+1}=7^6\)

Sao chẳng có ai T mik z bất công quá