-pi/2<=5-2x<=pi/2 /// *(-1)
pi/2>=2x-5>=-pi/2 /// +5
pi/2+5>=2x>=-pi/2+5 /// :2
pi/4+2.5>=x>=-pi/4+2.5
Ответ: [-pi/4+2.5;pi/4+2.5]
6^-1*2^-1 = 1/6*1/2=1/12
1/12:1/12^3=1/12*12^3/1 = 12^3/12^1 = 12^3-1 = 12^2 = 144.
1) x⁴-4x²+4=0
(x²-2)²=0
x²-2=0
x²=2
x=±√2
2) (16a²-8a+1)/(1-4a+x-4ax) = (4a-1)²/[(1-4a)(1+x)] = (1-4a)/(1+x)
1. a). (x + 8)(x + 2) = x² + 8x + 2x + 16 = x² + 10x + 16;
б). (a - b)(3b - 2a) = 3ab - 3b² - 2a² + 2ab = -2a² + 5ab - 3b²;
в). 2x - (x - 3)(x² + 2) = 2x - (x³ - 3x² + 2x - 6) =
= 2x - x³ + 3x² - 2x + 6 = -x³ + 3x² + 6;
2. a). m⁴ - 5m³ + m - 5 = m³(m - 5) + 1·(m - 5) = (m³ + 1)(m - 5) =
= (m + 1)(m² - m + 1)(m - 5);
б). 3a - 15 + ax - 5x = 3(a - 5) + x(a - 5) = (3 + x)(a - 5);
в). am + m - n + 3m - 3n - an = a(m - n) + 3(m - n) + 1(m - n) =
= (a + 4)(m - n);
3. (x - 1)(x - 2) - x² = 2
x² - x - 2x + 2 - x² = 2
-3x = 0
x = 0
Ответ: б). {0}