Lời giải:

$3^{2x+2}=9^{x+3}$

$3^{2x+2}=(3^2)^{x+3}=3^{2(x+3)}=3^{2x+6}$

$\Rightarrow 2x+2=2x+6$

$\Rightarrow 2=6$ (vô lý)

Vậy không có x thỏa mãn đề.

`@` `\text {Ans}`

`\downarrow`

`a)`

\(5^x+5^{x+2}=650\)

`\Rightarrow 5^x + 5^x . 5^2 = 650`

`\Rightarrow 5^x . (1 + 5^2) = 650`

`\Rightarrow 5^x . 26 = 650`

`\Rightarrow 5^x = 650 \div 26`

`\Rightarrow 5^x = 25`

`\Rightarrow 5^x = 5^2`

`\Rightarrow x = 2`

Vậy, `x = 2`

`b)`

`(4x + 1)^2 = 25.9`

`\Rightarrow (4x + 1)^2 = 225`

`\Rightarrow (4x + 1)^2 = (+-15^2)`

`\Rightarrow`\(\left[{}\begin{matrix}4x-1=15\\4x-1=-15\end{matrix}\right.\)

`\Rightarrow `\(\left[{}\begin{matrix}4x=16\\4x=-14\end{matrix}\right.\)

`\Rightarrow `\(\left[{}\begin{matrix}x=4\\x=-\dfrac{7}{2}\end{matrix}\right.\)

Vậy, `x \in`\(\left\{-\dfrac{7}{2};4\right\}\)

`c)`

\(2^x+2^{x+3}=144\)

`\Rightarrow 2^x + 2^x . 2^3 = 144`

`\Rightarrow 2^x . (1 + 2^3) = 144`

`\Rightarrow 2^x . 9 = 144`

`\Rightarrow 2^x = 144 \div 9`

`\Rightarrow 2^x = 16`

`\Rightarrow 2^x = 2^4`

`\Rightarrow x = 4`

Vậy, `x = 4`

`d)`

\(3^{2x+2}=9^{x+3}\)

`\Rightarrow `\(3^{2x+2}=\left(3^2\right)^{x+3}\)

`\Rightarrow `\(3^{2x+2}=3^{2x+6}\)

`\Rightarrow 2x + 2 = 2x + 6`

`\Rightarrow 2x - 2x = 6 - 2`

`\Rightarrow 0 = 4 (\text {vô lý})`

Vậy, `x` không có giá trị nào thỏa mãn.

`e)`

\(x^{15}=x^2\)

`\Rightarrow `\(x^{15}-x^2=0\)

`\Rightarrow `\(x^2\cdot\left(x^{13}-1\right)=0\)

`\Rightarrow `\(\left[{}\begin{matrix}x^2=0\\x^{13}-1=0\end{matrix}\right.\)

`\Rightarrow `\(\left[{}\begin{matrix}x=0\\x^{13}=1\end{matrix}\right.\)

`\Rightarrow `\(\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)

Vậy, `x \in`\(\left\{0;1\right\}.\)

\(a,5^x+5^{x+2}=650\\ \Rightarrow5^x+5^x.5^2=650\\ \Rightarrow5^x\left(1+5^2\right)=650\\ \Rightarrow5^x.26=650\\ \Rightarrow5^x=25\\ \Rightarrow5^x=5^2\\ \Rightarrow x=2\)

\(b,\left(4x+1\right)^2=25.9\\\Rightarrow\left(4x+1\right)^2=225\\ \Rightarrow\left[{}\begin{matrix}4x+1=15\\4x+1=-15\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{7}{2}\\x=-4\end{matrix}\right.\)

\(c,2^x+2^{x+3}=144\\ \Rightarrow2^x+2^x.2^3=144\\ \Rightarrow2^x\left(1+2^3\right)=144\\ \Rightarrow2^x=144:\left(1+2^3\right)\\ \Rightarrow2^x=16\\ \Rightarrow2^x=2^4\\ \Rightarrow x=4\)

\(d,3^{x+2}=9^{x+3}\\ \Rightarrow3^{x+2}=\left(3^2\right)^{x+3}\\ \Rightarrow3^{x+2}=3^{2x+6}\\ \Rightarrow x+2=2x+6\\ \Rightarrow x-2x=6-2\\ \Rightarrow-x=4\\ \Rightarrow x=-4\)

\(e,x^{15}=x^2\\ \Rightarrow x^{15}-x^2=0\\ \Rightarrow x^2\left(x^{13}-1\right)=0\\ \Rightarrow\left[{}\begin{matrix}x^2=0\\x^{13}-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)

a: =>5^x+5^x*25=650

=>5^x*26=650

=>5^x=25

=>x=2

b: =>4x+1=15 hoặc 4x+1=-15

=>4x=-16 hoặc 4x=14

=>x=7/2 hoặc x=-8

c: =>2^x*9=144

=>2^x=16

=>x=4

d: =>2x+2=2x+6

=>2=6(loại)

e: =>x^2(x^13-1)=0

=>x=0 hoặc x=1

\(f,\left(2x+1\right)^3=343\\\Rightarrow \left(2x+1\right)^3=7^3\\ \Rightarrow2x+1=7\\ \Rightarrow2x=6\\ \Rightarrow x=3\\ g,\left(x-1\right)^3=125\\ \Rightarrow\left(x-1\right)^3=5^3\\ \Rightarrow x-1=5\\ \Rightarrow x=6\\ h,2^{x+2}-2^x=96\\ \Rightarrow2^x.2^2-2^x=96\\ \Rightarrow2^x.\left(2^2-1\right)=96\\ \Rightarrow2^x=96:\left(2^2-1\right)\\ \Rightarrow2^x=32\\ \Rightarrow2^x=2^5\\ \Rightarrow x=5\)

\(i,\left(x-5\right)^4=\left(x-5\right)^6\\ \Rightarrow\left(x-5\right)^4\left(1-\left(x-5\right)^2\right)=0\\\Rightarrow\left[{}\begin{matrix}\left(x-5\right)^4=0\\1-\left(x-5\right)^2=0\end{matrix}\right. \\ \Rightarrow\left[{}\begin{matrix}x-5=0\\x-5=1\\x-5=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=5\left(t/m\right)\\x=6\left(t|m\right)\\x=4\left(loại\right)\end{matrix}\right.\)

\(j,720:\left[41-\left(2x-5\right)\right]=2^3.5\\ \Rightarrow720:\left(41-2x+5\right)=40\\ \Rightarrow\left(46-2x\right)=720:40\\ \Rightarrow46-2x=18\\ \Rightarrow2x=46-18=28\\ \Rightarrow x=28:2=14\)

@seven

f: =>2x+1=7

=>2x=6

=>x=3

g: =>x-1=5

=>x=6

h: =>2^x*3=96

=>2^x=32

=>x=5

i: =>(x-5)^4*[(x-5)^2-1]=0

=>(x-5)(x-4)(x-6)=0

=>x=5;x=4;x=6

j: =>41-(2x-5)=720:40=18

=>2x-5=23

=>2x=28

=>x=14

f)

`(2x+1)^3=343`

`(2x+1)^3=7^3`

`=>2x+1=7`

`2x=7-1`

`2x=6`

`x=6:2`

`x=3`

g)

`(x-1)^3 =125`

`(x-1)^3 =5^3`

`=>x-1=5`

`x=6`

h)

`2^(x+2)-2^x=96`

`2^x *2^2 -2^x =96`

`2^x (2^2 -1)=96`

`2^x *3=96`

`2^x =32`

`2^x =2^5`

`=>x=5`

i)

`(x-5)^4 =(x-5)^6` (`x>=5`)

`(x-5)^6 -(x-5)^4 =0`

`(x-5)^4 [(x-5)^2 -1]=0`

`=>x-5=0` hoặc `(x-5)^2 -1=0`

`<=>x=5` hoặc `(x-5)^2 =1`

`<=>x=5` hoặc `x-5=1` hoặc `x-5=-1`

`<=>x=5` hoặc `x=6` hoặc `x=4`

j)

`720:[41-(2x-5)]=2^3 *5`

`720:[41-(2x-5)]=8*5`

`720:[41-(2x-5)]=40`

`41-(2x-5)=720:40`

`41-(2x-5)=18`

`2x-5=41-18`

`2x-5=23`

`2x=28`

`x=14`

a, 2¹⁰⁰ và 1024⁹

    1024⁹ = (2¹⁰)⁹ = 2⁹⁰

     2¹⁰⁰   > 2⁹⁰

Vậy 2¹⁰⁰ > 2⁹⁰

b, 5³⁰ và 6.5²⁹

    6.5²⁹  > 5.5²⁹  = 5³⁰ 

     vậy 5³⁰  < 6.5²⁹

 c, 2⁹⁸ và 9⁴⁹

    (2²)⁴⁹ = 4⁴⁹ < 9⁴⁹ 

     vậy: 2⁹⁸ < 9⁴⁹

d, 10³⁰ và 2¹⁰⁰

    (10³)¹⁰ = 1000¹⁰ 

      2¹⁰⁰ = (2¹⁰)¹⁰ = 1024¹⁰

     Vì 1000¹⁰ < 1024¹⁰ 

     Nên 10³⁰ < 2¹⁰⁰

a,3²⁰ và 27⁴

3²⁰=(3⁵)⁴=243⁴>27⁴

Vậy 3²⁰>27⁴

b,5³⁴ và 25x5³⁰

25x5³⁰=5²x5³⁰=5³²<5³⁴

=>5³⁴>25x5³⁰.

c,2²⁴và 26⁶

2²⁴=(2⁴)⁶=16⁶<26⁶

=>2²⁴<26⁶

d,10³⁰và 4⁵⁰

10³⁰=(10³)¹⁰=1000¹⁰

4⁵⁰=(4⁵)¹⁰=1024¹⁰

Vì 1000¹⁰<1024¹⁰nên 10³⁰<4⁵⁰.

e,2³⁰⁰và 3²⁰⁰

2³⁰⁰=(2³)¹⁰⁰=8¹⁰⁰

3²⁰⁰=(3²)¹⁰⁰=9¹⁰⁰

Vì 8¹⁰⁰<9¹⁰⁰ nên 2³⁰⁰<3²⁰⁰

gọi Ox mk ghi nhầm nha

Bạn tự vẽ hình nhé.

1, ta có AOB  VÀ BOC  là 2 góc kề bù nên ta có:

AOB+BOC=180 độ

mà BOC=2 AOB<=> AOB+2AOB=180<=> 3AOB=180

<=> AOB=60 ĐỘ<=> BOC= 60 x 2=120 độ

vậy aob=60 độ; boc=120 độ

2, ta có OX là tia phân giác <=> BOX=1/2 AOB=30 ĐỘ

<=> COX= 30+120=150 độ

vậy COX =  150 độ

~~~~ chúc bn lul lul hok tốt ~~~~

a, 3\(^x\).3 = 243

    3\(^x\)     = 243: 3

     3\(^x\)    = 81

     3\(^x\)     = 3⁴

      \(x\)      = 4

b, \(x^{20}\) = \(x\) 

    \(x^{20}\) - \(x\) = 0

    \(x\)(\(x^{19}\) - 1) = 0

     \(\left[{}\begin{matrix}x=0\\x^{19}=1\end{matrix}\right.\)

     \(\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)

vậy \(\in\) {0; 1}

c, 2\(^x\).16² = 1024

    2\(^x\)        = 1024: 16²

    2\(^x\)       = 2¹⁰: 2⁸

    2\(^x\)       = 2²

      \(x\)       = 2

d, 64.4\(^x\)   = 16⁸

         4\(^x\)   = 16⁸:64

         4\(^x\)   = (4²)⁸ : 4³

         4\(^x\)   =   4¹³

           \(x\)  = 13

e, 2\(^x\).4 = 128

    2\(^x\)    = 128:4

     2\(^x\)    = 32

     2\(^x\)     = 2⁵

      \(x\)      = 5