Question

) Cho P(x) = 4x² - 4 + 3x³ + 2x + x⁵ và Q(x) = 3x - 2x³ + 4 - x⁴ + x^5.

a) Sắp xếp hai đa thức theo lũy thừa giảm của biến.

b) Tính P(x) + Q(x).

Answer 1

P(x)=x^5+3x^3+4x^2+2x-4

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

P(x)+Q(x)=2x^5-x^4+x^3+4x^2+5x

Answer 2

a, P(x)= x^5+3x^3+4x^2+4x-4

   Q(x)= x^5-x^4-2x^3+3x-4

b, P(x)+Q(x)= 2x^5-x^4+x^3+4x^2+x-8

Answer 3

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

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

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

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

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

Answer 4

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

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

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

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

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

Answer 5

a.P(x)= x⁵+3x³+4x²+2x-4

Q(x)=x⁵- x⁴ -2x³ +3x +4

b.P(x)+Q(x)=2x⁵+x³+4x²+5x-x⁴

Answer 6

 a, P(x)= x^5+3x^3+4x^2+4x-4

   Q(x)= x^5-x^4-2x^3+3x-4

b, P(x)+Q(x)= 2x^5-x^4+x^3+4x^2+x-8

Answer 7

a)  sau khi sắp xếp 2 đa thức theo lũy thừa giảm của biến ,ta có:

P(x) =   x⁵ + 3x³ + 4x² + 2x - 4

Q(x) =   x⁵ - x⁴ - 2x³ + 3x + 4

b) tính P(x) + Q(x)

cách 1:  P(x) + Q(x) =   ( x⁵ + 3x³ + 4x² + 2x - 4 ) + ( x⁵ - x⁴ - 2x³ + 3x + 4 )

                               =    x⁵ + 3x³ + 4x² + 2x - 4 + x⁵ - x⁴ - 2x³ + 3x +4

                               =    ( x⁵ + x⁵) - x⁴ + (3x³ - 2x³ ) + 4x² + (2x + 3x) + ( - 4 + 4 )

                                =     2x⁵ - x⁴ + x³ + 4x² + 5x

cách 2 :

P(x)          = x⁵      + 3x³ + 4x² + 2x - 4

+

Q(x)         = x⁵  - x⁴ - 2x³          + 3x + 4

P(x)+Q(x) =2x⁵ - x⁴ + x³ + 4x² + 5x