2.1.
(3 - y)/(y² - xy) + (x - 3)/(xy - x²) = (3 - y)/y(y - x) + (x - 3)/x(y - x) = (x(3 - y) + y(x - 3)) / xy(y - x) = (3x - xy + yx - 3y)/xy(y - x) = 3(x - y) / xy(y - x) = - 3/xy
2.2.
По теореме Виета:
x₁ + x₂ = -p
x₁*x₂ = -6
1,5*x₂ = -6
p = - (x₁ + x₂)
x₂ = -4
p = - (4 + 1,5) = -5,5