5.
w(x) = 2x³ - x² + x - 4
w(0) = -4
w(2) = 2(2³) - (2)² + 2 - 4 = 2*8 - 4 + 2 - 4 = 16 - 6 = 10
6.
u(x) = 9x⁷ - 13x³ + 10x² - 2 ; stopień 7 ; współczynniki:
a₀ = -2
a₁ = 0
a₂ = 10
a₃ = -13
a₄ = 0
a₅ = 0
a₆ = 0
a₇ = 9
w(x) = -9x⁷ + 6x⁴ - 12x² + 7 ; stopień 7 ; współczynniki:
a₀ = 7
a₂ = -12
a₃ = 0
a₄ = 6
a₇ = -9
u(x) + w(x) = 9x⁷ - 13x³ + 10x² - 2 + (-9x⁷ + 6x⁴ - 12x² + 7) = 9x⁷ - 13x³ + 10x² - 2 -9x⁷ + 6x⁴ - 12x² + 7 = 6x⁴ - 13x³ - 2x² + 5
