Question

ajutati-ma si pe mine la exercițiul numărul 4. dau coroana!

Answer 1

 

$\displaystyle\\3^x=a\\\\a)~~~3^{x+1}=3\cdot 3^x=\boxed{\bf3a}\\\\b)~~~2\cdot9^x=2\cdot\Big(3^2\Big)^x=2\cdot3^{2x}=2\cdot\Big(3^x\Big)^2=\boxed{\bf2a^2}$