Question

sejam os polinômios p(x)=5x³-3x²+6x-11,Q(x)= - 8x³+2x²-9x+10 e R(x)= -3x²+2x caucule valor de:
a) 2p(x) + 3Q(x) - 5R(x)

b)P(-2)+2Q(-1) -2R(-3)

Answer 1

a)    2p(x) + 3q(x) - 5r(x) =

   = 2 × (5x³-3x²+6x-11) + 3 × (-8x³+2x²-9x+10) - 5 × (-3x²+2x) =

   = (10x³-6x²+12x-22) + (-24x³+6x²-27x+30) - (-15x²+10x) =

   = 10x³ - 6x² + 12x - 22 - 24x³ + 6x² - 27x + 30 + 15x² - 10x =

   = 10x³ - 24x³ - 6x² + 6x² + 15x² + 12x - 27x - 10x - 22 + 30 =

   = -14x³ + 15x² - 25x + 8

b)    p(-2) + 2q(-1) - 2r(-3) =

= [5×2³-3×2²+6×2-11] + 2×[-8×(-1)³+2×(-1)²-9×(-1)+10] - 2×[-3×(-3)²+2×(-3)] =

   = (5×8-3×4+12-11) + 2×(-8×(-1)+2×1+9+10) - 2×(-3×9-6) =

   = (40-12+12-11) + 2×(8+2+9+10) - 2×(-27-6) =

   = 29 + 2×29 - 2×(-33) =

   = 29 + 58 + 66 =

   = 153