при x=4, y=-2

Решение:

• 1) -2x - y = -2(4) - (-2) = -8 + 2 = -6
• 2) -2(x - y) = -2(4 - (-2)) = -2(4 + 2) = -2(6) = -12
• 3) rac{x+y}{2y} = rac{4 + (-2)}{2(-2)} = rac{2}{-4} = -rac{1}{2}
• 4) |x| - 2|y| = |4| - 2|-2| = 4 - 2(2) = 4 - 4 = 0
• 5) rac{y2}{x} = rac{(-2)2}{4} = rac{4}{4} = 1
• 6) -3x2 = -3(4)2 = -3(16) = -48

Ответ: 1) -6, 2) -12, 3) -1/2, 4) 0, 5) 1, 6) -48