6 ⋅ 8^{x-1} + 8^{x+1} = 6 ⋅ 8^{19} + 8^{21}

giải hộ vs !!
----- Nội dung ảnh -----
6 ⋅ 8^{x-1} + 8^{x+1} = 6 ⋅ 8^{19} + 8^{21}.