Question

tìm x

a , \(^{3^{x-1}+5.3^{x-1}=162}\)

b , (x-1) . ( x - 3 )

Answer 1

3^{x - 1} + 5.3^{x - 1}=162

3^{x - 1} .(1+5)=162

3^{x - 1}=27

3^x :3¹=27

3^x=81

3^x=3⁴

=>  x=4

Answer 2

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

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

\(\Rightarrow3^{x-1}.6=162\)

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

\(\Rightarrow x-1=3\)

\(\Rightarrow x=4\)

Câu b tự làm nhé