Question

Cho 3 đa thức:

B(x) = 12x⁴ + 6x³ - \(\frac{1}{2}\)x + 3

C(x) = -12x⁴ - 2x³ + 5x + \(\frac{1}{2}\)

Tính B(x) + C(x) và B(x) - C(x)

Answer 1

B(x) + C(x)=

( 12x⁴ + 6x³ - \(\frac{1}{2}\)X+ 3)+(-12x⁴ - 2x³ + 5x + \(\frac{1}{2}\))

=12x⁴ + 6x³ - \(\frac{1}{2}\)X+ 3-12x⁴ - 2x³ + 5x + \(\frac{1}{2}\)

=(12x⁴-12x⁴)+(6x³-2x³)+(-\(\frac{1}{2}\)+ \(\frac{1}{2}\))+3+5x

=4x³+3+5x

B(x) - C(x)=

( 12x⁴ + 6x³ - \(\frac{1}{2}\)X+ 3)-(-12x⁴ - 2x³ + 5x + \(\frac{1}{2}\))

=12x⁴ + 6x³ - \(\frac{1}{2}\)X+ 3+12x⁴ + 2x³ - 5x - \(\frac{1}{2}\)

=(12x⁴⁺12x⁴)+(6x³⁺2x³)+(-\(\frac{1}{2}\)- \(\frac{1}{2}\))+3-5x

=24x⁴+8x³-1+3-5x

=24x⁴+8x³⁺(-1+3)-5x

=24x⁴+8x³+2-5x