tentukan himpunan penyelesaian persamaan eksponen berikut. please yang bisa bantu yaa

a) 9^2x-4 = ( 1/27)^x²-4
(3²)^2x-4 = ( 3-³)^x²-4
=> 2(2x - 4) = - 3(x² - 4)
=> 4x - 8 = - 3x² + 12
=> 3x² + 4x - 8 - 12 = 0
=> 3x² + 4x - 20 = 0
=> ( 3x + 10)(x - 2) = 0
=> 3x = - 10 atau x = 2
=> x = - 10/3
hp = ( - 10/3 , 2 )

b) 8^x+2 = ³√64^x+5
(2³)^x+2 = ³√(2^6)^x+5
2^3x+6 = ³√2^6x+30
=> 3x + 6 = ( 6x + 30) ÷ 3
=> 3x + 6 = 2x + 10
=> 3x - 2x = 10 - 6
=> x = 4