Question

Answer 1

a 

          f(x)= 5x² -  2x +5

        +g(x)= 5x² - 6x -1/3

----------------------------------

   f(x)+g(x)=10x²-8x -14/3

b

          f(x)= 5x² -  2x +5

        -g(x)= 5x² - 6x -1/3

----------------------------------

   f(x)-g(x)=         4x +16/3

c ta có 

4x+16/3=0

4x=0+16/3

4x=16/3

x=16/3:4

x=4/3

vậy x=4/3 là nghiệm của đa thức f(x)-g(x)

Answer 2

a)

` f(x) = 5x^2 - 2x + 5`

` g(x) = 5x^2 - 6x - 1/3`

`f(x) + g(x) = 5x^2 - 2x + 5 +  5x^2 - 6x - 1/3`

` f(x) + g(x) = 10x^2 - 8x - 14/3 `

 

b)

` f(x) = 5x^2 - 2x + 5`

` g(x) = 5x^2 - 6x - 1/3`

`f(x) - g(x) = 5x^2 - 2x + 5 -  5x^2 - 6x - 1/3`

` f(x) - g(x) = 4x + 16/3`

 

c)

`  4x + 16/3`

` 4x + 16/3 = 0`

` 4x = -16/3`

` x = -16/3 : 4`

`x= -4/3`