<em>х⁴*у⁴/((х²)²)=у⁴, при условии х≠0</em>
<em>у⁴=16</em>
<em>у=±2</em>
<em>Ответ у₁=2</em>
<em> у₂=-2</em>
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√72-√288 sin в квадрате 15П/8√72 -√(288) *sin²15π/8 = √72(1 - 2sin²(2π -π/8)) =6√2(1 -2sin²π/8) =
(6√2)*cos2*π/8= (6√2)*cosπ/4 =(6√2)*(1/√2) = 6.
Решение во вложениииииииииииииии
(x^2 + 6x)^2 + 2(x^2 + 6x + 9) - 81 = 0
x^2 + 6x = a,
x^2 +6x + 9 = a + 9,
a^2 + 2(a + 9) - 81 = 0,
a^2 + 2a - 63 = 0
а1 = -9
a2 = 7
x^2 + 6x = -9
x^2 + 6x + 9 = 0
x = -3
x^2 + 6x = 7
x^2 + 6x -7 = 0
x1 = -7
x2 = 1
ответ. -7; -3; 1.