помогите решить уравнения

4^9+x=16

х = 16 - 4^9

x = 4^2 - (2^9) ^2 = (4 - 2^9) (4 + 2^9)

2^9 = 2^5 * 2^4 = 32*16 = 512

x = (4-512) (4+512) = - 508*516 = - (500+8) (500+16) = - (500*500 + 500 * (8+16) + 8*16) =

= - (250 000 + 500*24 + 128) = - (250 000 + 12 000 + 128) = - 262128

4^ (9+x) = 16

2^2 (9+x) = 2^4

2^ (18+2x) = 2^4

18+2x=4

14+2x=0

x=-14/2

x=-7