a) G(x) = 2x⁵-4x⁴-10x³+3x²-4x-8

      H(x) = x⁵-2x⁴-5x³+x²+7x-4

b) G(x)+H(x)=3x⁵-6x⁴-15x³+4x²+3x-12

    G(x)-H(x) =x⁵-2x⁴-5x³+2x²-11x-4

c) G(x) = 2H(x)

2x⁵-4x⁴-10x³+3x²-4x-8=2( x⁵-2x⁴-5x³+x²+7x-4)

2x⁵-4x⁴-10x³+3x²-4x-8-2( x⁵-2x⁴-5x³+x²+7x-4)=0

2x⁵-4x⁴-10x³+3x²-4x-8-2x⁵+4x⁴⁺10x³-2x²-14x+8=0

x²-18x=0

x(x-18)=0

x=0 hoặc x-18=0

                x=18

a: \(h\left(x\right)=7x^5+x^4-2x^3+4+x^4+6x^3-9x^2-2x-1=7x^5+2x^4+4x^3-9x^2-2x+3\)

b: \(h\left(x\right)=7x^5+x^4-2x^3+4-x^4-6x^3+9x^2+2x+1=7x^5-8x^3+9x^2+2x+5\)

h(x) + g(x) = f(x)

=> h(x)= f(x) - g(x) = \(3x^4+2x^2-2x^4+x^2-5x-\left(x^4-x^2-2x+6+3x^2\right)=x^2-3x-6\)\(h\left(-\dfrac{1}{3}\right)=\left(-\dfrac{1}{3}\right)^2-3\left(-\dfrac{1}{3}\right)-6=\dfrac{-44}{9}\)

\(h\left(\dfrac{3}{2}\right)=\left(\dfrac{3}{2}\right)^2-3\cdot\dfrac{3}{2}-6=-\dfrac{33}{4}\)

\(x^2-3x-6=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3+\sqrt{33}}{6}\\x=\dfrac{3-\sqrt{33}}{6}\end{matrix}\right.\)

a: \(P\left(x\right)=x^4+x^3-x^2+2x-5\)

\(Q\left(x\right)=x^4+5x^3-3x^2-2x-5\)

b: \(H\left(x\right)=P\left(x\right)-Q\left(x\right)=-4x^3+2x^2+4x\)

c: Bậc của H(x) là 3

a)\(P\left(x\right)=x^4+x^3-x^2+2x-5\)

\(Q\left(x\right)=x^4+5x^3-3x^2-2x-5\)

b)\(H\left(x\right)=x^4+x^3-x^2+2x-5-x^4-5x^3+3x^2+2x+5\)

\(H\left(x\right)=-4x^3+2x^2+4x\)

c) Bậc : 3

d)\(H\left(3\right)=-4.3^3+2.3^2+4.3=-4.27+2.9+12=-108+18+12=-78\)

\(H\left(-3\right)=-4.\left(-3\right)^3+2.\left(-3\right)^2+4.\left(-3\right)\)

\(H\left(-3\right)=-4.\left(-27\right)+2.9-12=108+18-12=114\)

\(H\left(\dfrac{1}{3}\right)=-4.\left(\dfrac{1}{3}\right)^3+2.\left(\dfrac{1}{3}\right)^2+\dfrac{4.1}{3}=-\dfrac{4.1}{27}+\dfrac{2.1}{9}+\dfrac{4}{3}\)

\(H\left(\dfrac{1}{3}\right)=-\dfrac{4}{27}+\dfrac{6}{27}+\dfrac{36}{27}=\dfrac{38}{27}\)

\(H=\left(x-1\right)^3-\left(x+2\right)\left(x^2-2x+4\right)+3\left(x+4\right)\left(x-4\right)\)

\(=x^3-3x^2+3x-1-x^3-8+3\left(x^2-16\right)\)

\(=-3x^2+3x-9+3x^2-48=3x-57\)

Khi x=1/-2 thì \(H=3\cdot\dfrac{-1}{2}-57=-1,5-57=-58,5\)

Đầu tiên tính h(x) em nhé. Ta đc h(x)=\(8x^4-6x^3-6x^2-2x+1\) 
Đến đây thay \(x=\frac{-3}{2}\) vào là tính đc thôi
Dễ mà em "=.="

a: Q(x)=3x^4+x^3+2x^2+x+1-2x^4+x^2-x+2

=x^4+x^2+3x^2+3

b: H(x)=2x^4-x^2+x-2-x^4+x^3-x^2+2

=x^4+x^3-2x^2+x

c: R(x)=2x^3+x^2+1+2x^4-x^2+x-2

=2x^4+2x^3+x-1