Question

9^(x+1)-2*3^(x+2)+5=0
срочно

Answer 1

9^(x+1)-2*3^(x+2)+5=0

9*9^x-18*3^x+5=0

3^x = t > 0

9t² - 18t + 5 = 0

D = 324 - 180 = 144

t12 =( 18 +- 12)/18 = 1/3   5/3

1. t = 1/3

3^x = 1/3

x = -1

2. t = 5/3

3^x = 5/3

log(3) 3^x = log(3) 5/3

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

ответ -1,  log(3) 5  - 1