<span>х^2 = 7
х= плюс минус корень из 7</span>
A) 2 ²/₃ x²y⁸ * (-1 ¹/₂ xy³)⁴=⁸/₃ x²y⁸ * (-³/₂ xy³)⁴=
=⁸/₃ x²y⁸ * ⁸¹/₁₆ x⁴y¹² = ²⁷/₂ x⁶y²⁰ = 13.5x⁶y²⁰
б) x^(n-2) * x^(3-n) * x=x^(n-2+3-n+1)=x²
3x^2 - 6x = x - 4
3x^2 - 6x - x + 4 = 0
3x^2 - 7x + 4 = 0
D = 49 - 48 = 1
x1 = (7 + 1)/6 = 8/6 = 4/3
x2 = (7 - 1)/6 = 6/6 = 1
Смотри...................