Có nha bạn.

\(Ư\left(2\right)=\left\{\pm1;\pm2\right\}\)

Cảm ơn nha

\(3^{x+1}=81\)

\(3^{x+1}=3^4\)

\(=>x+1=4\)

\(x=4-1\)

\(=>x=3\)

\(3^{x+1}=81\)

\(3^{x+1}=3^4\)

\(x+1=4\)

\(x=4-1=3\)

\(2^5-500:25+3^2\cdot2^3\\ =32-20-9\cdot8\\ =12+72\\ =84\)

( 2^5 . 2^3 ) - 500 : 25 + 3^2 = 2^8 - 20 + 3^2 

= ( 8^2 - 3^2 )+ 20 = 5^2 + 20 = 25+20 = 45 

\(215=2\cdot10^2+1\cdot10+5\cdot10^0\)

\(902=9\cdot10^2+2\cdot10^0\)

\(2020=2\cdot10^3+2\cdot10\)

\(883011=8\cdot10^5+8\cdot10^4+3\cdot10^3+10+1\cdot10^0\)

\(5n⋮2\Rightarrow n⋮2\)

\(\Rightarrow n=\left\{2;-2\right\}\)

Mọi số tự nhiên $n$ chẵn đều thỏa mãn đề bài.

a) \(\left(x-1\right)^3=8=2^3\)

\(x-1=2\)

\(x=2+1=3\)

b) \(7^{2x-6}=49=7^2\)

\(2x-6=2\)

\(2x=6+2=8\)

\(x=8:2=4\)

c) \(\left(2x-14\right)^7=128=2^7\)

\(2x-14=2\)

\(2x=14+2=16\)

\(x=16:2=8\)

d) \(x^4\cdot x^5=5^3\cdot5^6=5^4\cdot5^5\)

\(x=5\)

e) \(3\cdot\left(x+2\right):7\cdot4=120\)

\(x+2=120:3\cdot7:4\)

\(x+2=70\)

\(x=70-2=68\)

Lời giải:

a. $(x-1)^3=8=2^3$
$\Rightarrow x-1=2$

$\Rightarrow x=3$

b. $7^{2x-6}=49=7^2$
$\Rightarrow 2x-6=2$

$\Rightarrow 2x=8$

$\Rightarrow x=4$

c. $(2x-14)^7=128=2^7$

$\Rightarrow 2x-14=2$

$\Rightarrow 2x=16$

$\Rightarrow x=18$

d.

$x^4.x^5=5^3.5^6$

$x^9=5^9$

$\Rightarrow x=5$

e. 

$3(x+2):7=120:4=30$

$3(x+2)=30.7=210$

$x+2=210:3=70$

$x=70-2=68$

\(B\left(5\right)=\left\{0;5;10;15;20;...\right\}\)

\(B\left(-5\right)=\left\{0;-5;-10;-15;-20;...\right\}\)