2㏒₇16 2㏒₇2⁴
----------------------------------------- = ------------------------------------ =
㏒₃(√10 -1) + ㏒₃(√10 +1) ㏒₇2 ㏒₃((√10 -1) *(√10 +1) )㏒₇2
2*4㏒₇2 8 ㏒₇2 8 ㏒₇2
= ---------------------- = ---------------- = ------------------- = 8/2 =4
㏒₃(10 -1) *㏒₇2 ㏒₃9 *㏒₇2 2㏒₃3 *㏒₇2
(3^11×9^3)/27^5. (3^11×3^6)/3^15= 3^17/3^15=3^2=9
ответ: 9
1-2sin²x+5sinx+2=0
2sin²x+5sinx+1=0
пусть sinx=k
2k²+5k+1=0
D=25-8=17
x1=(-5+√17):4
x2=(-5-√17):4
2x^2 - 3x - 6 = x^2 - 4x - 2 + x^2
2x^2 - 3x - 6 = 2x^2 - 4x - 2
- 3x - 6 = - 4x - 2
- 3x + 4x = 6 - 2
x = 4