Question

các bn giúp mk nha 

a) \(4^x+4^{x+3}=4160\)

b) \(5^x+5^{x+2}=650\)

Answer 1

a) 4^x + 4^{x + 3}  = 4160

4^x + 4^x . 4³  = 4160

4^x .( 1 + 4³ ) = 4160

4^x . 65 = 4160 

4^x  = 4160 : 65

4^x = 64 => 4^x = 4³ => x = 3

b) 5^x + 5^{x + 2} = 650

5^{x  +} 5^x . 5² = 650

5^x . ( 1 + 5² ) = 650

5^x . 26 = 650 => 5^x = 650 : 26 = 25 => 5^x  = 5² => x = 2

Answer 2

a) 4³ + 4³⁺³ = 4160

b) 5² + 5²⁺² = 650

Chúc bạn học tốt!

Answer 3

\(a)4^x+4^{x+3}=4160\)

\(\Rightarrow4^x+4^x\cdot4^3=4160\)

\(\Rightarrow4^x+(1\cdot4^3)=4160\)

\(\Rightarrow4^x+(1\cdot64)=4160\)

\(\Rightarrow4^x+64=4160\)

\(\Rightarrow4^x=4160-64\)

\(\Rightarrow4^x=4096\)

\(\Rightarrow4^x=4^6\)

\(\Rightarrow x=6\)

Answer 4

Lộn , \(a)4^x+4^{x+3}=4160\)

\(\Rightarrow4^x+4^x\cdot4^3=4160\)

\(\Rightarrow4^x\cdot(1+64)=4160\)

\(\Rightarrow4^x\cdot65=4160\)

\(\Rightarrow4^x=4160\div65\)

\(\Rightarrow4^x=64\)

\(\Rightarrow4^x=4^3\)

\(\Rightarrow x=3\)

Bài b tự xử