log²(1/2) x + 3log(1/2) x + 2 = 0
x > 0
log(1/2) x = t
t² + 3t + 2 = 0
D = b² - 4ac = 9 - 8 = 1
t12 = (-3 +- 1)/2 = -1 -2
t1 = -1
log(1/2) x = -1
x = (1/2)^(-1)
x = 2
t2 = -2
log(1/2) x = -2
x = (1/2)^(-2)
x = 4
ответ 2 и 4
<span>2х-у=-12
х+2у=1 умножим на 2
2х-у=-12
2х+4у=2 вычтем из второго первое
4у-(-у)=2-(-12)
5у=14
у=14/5
<u>у=2.8</u>
х+2*12.8=1
х+25.6=1
х=1-25.6
<u>х=-24.6</u>
</span>
6+5х=-2х-1
5х+2х=-6-1
7х=-7
Х=-1
B₆ = √b₅*b₇ = 15
У нас ряд: ...; 25; 15; 9;...
q = 9/15 = 3/5
b₅ = b₁q⁴
25 = b₁*(3/5)⁴
b₁ = 25 : 625/81= 25*81/625 = 81/25
S₆ = 81/25*((3/5)⁶ -1)/(1 - 3/5) = 81*7448/15625