Question

1/ Tìm x biết

a) \(3^{x-1}+5.3^{x-1}=162\)

Answer 1

3^x-1.6=162

Answer 2

3^x-1 +5.3^x-1=(1+5).3^x-1=6.3^x-1=162

3^x-1=27

3^x-1=3^3

 =>x-1=3

x=2

Answer 3

Ta co :3^x-1*6=162

=>3^x-1=27

=>3^x-1=3^3

=>x-1=3

=>x=1 

cac ban

Answer 4

ak nham x=2 moi dung

Answer 5

=> \(3^x\div3+5\times3^x\div3=162\)

=> \(3^x\times\frac{1}{3}+5\times3^x\times\frac{1}{3}=162\)

\(3^x\times\left(\frac{1}{3}+\frac{5}{3}\right)=162\)

\(3^x\)=162\(\div\)2=81

x=4