7^ (x+2) - 14*7^x=5

-log7 (5-x) = log7 (2-1)

9^x+8*3^x=9

log1/2 (x+9) - log1/2 (8-3x) = 2

7^ (x+2) - 14*7^x=5

7^x*7^2-15*7^x=5

49*7^x-14*7^x=5

35*7^x=5

7^x=5/35

7^x=1/7

7^x=7^ (-1)

x=-1

-log7 (5-x) = log7 (2-1)

log7 1 / (5-x) = log7 (3)

1 / (5-x) = 3

1=15-3x

3x=14

x=14/3

9^x+8*3^x=9

(3^2) ^x+8*3^x=9

3^2x+8*3^x-9=0

обозначим 3^x=y

y^2+8y-9=0

D=100

y1=1 y2=-9

3^x=1 x=0

3^x=-9 - неверно

ответ х=0

log1/2 (x+9) - log1/2 (8-3x) = 2

log1/2 (x+9) / (8-3x) = log1/2 (1/4)

(x+9) / (8-3x) = 1/4

4 (х+9) = 8-3x

4 х-36=8-3 х

7 х=44

х=44/7