Question

Tìm số nguyên x, nếu biết: 

1) 2^x=4³

²⁾ (1/7)^x=(1/343)³

Answer 1

1) \(2^x=4^3\)

=> 2^x = (2²)³

=> 2^x = 2⁶

=> x = 6

2) \(\left(\frac{1}{7}\right)^x=\left(\frac{1}{343}\right)^3\)

=> \(\left(\frac{1}{7}\right)^x=\left[\left(\frac{1}{7}\right)^3\right]^3\)

=> \(\left(\frac{1}{7}\right)^x=\left(\frac{1}{7}\right)^9\)

=> x = 9

Answer 2

Bài làm:

1) \(2^x=4^3\)

\(\Leftrightarrow2^x=2^6\)

\(\Rightarrow x=6\)

2) \(\left(\frac{1}{7}\right)^x=\left(\frac{1}{343}\right)^3\)

\(\Leftrightarrow\left(\frac{1}{7}\right)^x=\left(\frac{1}{7}\right)^9\)

\(\Rightarrow x=9\)

Answer 3

1) 2^x = 4³

=> 2^x = (2²)³

=> 2^x = 2⁶

=> x = 6

2) \(\left(\frac{1}{7}\right)^x=\left(\frac{1}{343}\right)^3\)

=> \(\left(\frac{1}{7}\right)^x=\left[\left(\frac{1}{7}\right)^3\right]^3\)

=> \(\left(\frac{1}{7}\right)^x=\left(\frac{1}{7}\right)^9\)

=> x = 9

Answer 4

2^x=4^3

2^x=(2^2)^3

2^x=2^2×^3           chỗ này là mũ 2×mũ 3nha

2^x=2^6

x=6

vậy x=6

Answer 5

\(1)2^x=4^3\)

\(\Rightarrow2^x=\left(2^2\right)^3\)

\(\Rightarrow2^x=2^6\)

\(\Rightarrow x=6\)

\(2)\left(\frac{1}{7}\right)^x=\left(\frac{1}{343}\right)^3\)

\(\Rightarrow\left(\frac{1}{7}\right)^x=\left(\frac{1}{7}\right)^9\)

\(\Rightarrow x=9\)

Học tốt

Answer 6

(1/7)^x=(1/343)^3

(1/7)^x=[(1/7)^3]3

(1/7)^x=(1/7)^3×^3   chỗ này là mũ 3×mũ 3

(1/7)^x=(1/7)^9

x=9

vậy x=9

Answer 7

2^x = 4³

<=> 2^x = ( 2² )³

<=> 2^x = 2⁶

<=> x = 6

( 1/7 )^x = ( 1/343 )³

<=> ( 1/7 )^x = [ ( 1/7 )³ ]³

<=> ( 1/7 )^x = ( 1/7 )⁹

<=> x = 9