Question

помогите 9^х-6*3^х-27=0

Answer 1

$9^x-6cdot3^x-27=0, \ 3^{2x}-6cdot3^x-27=0, \ 3^x=a, a textgreater 0, \ a^2-6a-27=0, \ a_1=-3, a_2=9, \ 3^x=9, \ 3^x=9^2, \ x=2.$