x=10^5-10^5*3/10^5*11

x=10^5(1-3)/10^5(11)

=>x=-2/11

a) 5^{x + 1} - 2.5^x = 75

<=> 5^x.5 - 2.5^x = 75

<=> 5^x.3 = 75

<=> 5^x = 25

<=> 5^x = 5²

<=> x = 2

Vậy x = 2

b) 9^{x + 1} -  5.3^2x = 324

<=> (3²)^{x + 1} - 5.3^2x = 324

<=> 3^{2x + 2} - 5.3^2x = 324

<=> 3^2x.3² - 5.3^2x = 324

<=> 3^2x . 4 = 324

<=> 3^2x = 81

<=> 3^2x = 3⁴

<=> 2x = 4

<=> x = 2

Vậy x = 2

UIUYI

27^5.3^x=9^10

3^x=9^10:27^5

3^x=3^5

=> x=5

27⁵.3^x=9¹⁰

=>3¹⁵.3^x=3³⁰

=>3^x=3³⁰:3¹⁵

=>3^x=3¹⁵

=>x=15

27⁵.3^x=9¹⁰

(3³)⁵.3^x = (3²)¹⁰

3¹⁵.3^x = 3²⁰

3^x = 3²⁰:3¹⁵ (3^20-15)

3^x = 3⁵

<=> x = 5

\(9^{x+1}-5.3^{2x}=324=>9^x.9-5.\left(3^2\right)^x=324=>\left(3^2\right)^x.9-5.\left(3^2\right)^x=324\)

\(=>3^{2x}.\left(9-5\right)=324=>3^{2x}=\frac{324}{4}=81=3^4=>2x=4=>x=2\)

vậy x=2

tick nhé

Theo đề ta có:

\(5.3^{3x+2}-27^{x+1}=486\)

\(\Rightarrow5.27^x.9-27^x.27=486\)

\(\Rightarrow27^x\left(45-27\right)=486\)

\(\Rightarrow27^x.18=486\)

\(\Rightarrow27^x=\frac{486}{18}\)

\(\Rightarrow27^x=27\)

\(\Rightarrow27^x=27^1\)

\(\Rightarrow x=1\)

vậy \(x=1\)

Lời giải:

Gọi biểu thức là $A$

\(A=\frac{2^{10}.3^8+5.(2^2)^5.3^8}{2^{10}.(3^3)^3-2^{10}.(3^2)^4}=\frac{2^{10}.3^8+5.2^{10}.3^8}{2^{10}.3^9-2^{10}.3^{8}}\)

\(=\frac{2^{10}.3^8(1+5)}{2^{10}.3^8(3-1)}=\frac{6}{2}=3\)

Giang ho dai ca viet nham nhé:

\(5.3^x=8.3^9+7.27^3\)

<=> \(5.3^x=8.3^9+7.\left(3^3\right)^3\) <=> \(5.3^x=8.3^9+7.3^9\)

<=> \(5.3^x=15.3^9\) <=> \(3^x=3.3^9=3^{10}\) => x = 10

nhầm chỉnh lại :

\(5.3^x=8.3^9+7.27^3\Rightarrow5.3^x=8.3^9+7.3^9=15.3^9\Rightarrow15.3^{x-1}=15.3^9\Rightarrow3^{x-1}=3^9\Rightarrow x-1=9\Rightarrow x=10\)

Có 5.3^x=8.3^9+7.27^3

=>5.3^x=8.3^9+7.(3^3)^3

=>5.3^x=8.3^9+7.3^9

=>5.3^x=3^9.(8+7)

=>5.3^x=3^9.15

=>3^x=3^9.15:5

=>3^x=3^9.3

=>3^x=3^10

=>x=10

Vậy x=10

bn đăng ít thoi

a)5^x+5^x+2=650

\(\Rightarrow5^x\left(1+5^2\right)=650\)

\(\Rightarrow5^x\cdot26=650\)

\(\Rightarrow5^x=25\)

\(\Rightarrow5^x=5^2\)

\(\Rightarrow x=2\)

b)\(3^{x-1}+5\cdot3^{x-1}=162\)

\(\Rightarrow3^{x-1}\cdot\left(1+5\right)=162\)

\(\Rightarrow3^{x-1}\cdot6=162\)

\(\Rightarrow3^{x-1}=27\)

\(\Rightarrow3^{x-1}=3^3\)

\(\Rightarrow x-1=3\)

\(\Rightarrow x=4\)

c và d bài 1 có tại đây Câu hỏi của Vương Hàn - Toán lớp 7 | Học trực tuyến