Relax

Respuesta :

Answer: [tex]-2x^2-4x+40[/tex]

Step-by-step explanation:

Suppose the missing polynomial be f(x)

So, we can write

[tex]\Rightarrow f(x)-(20-4x+5x^2)=20-7x^2\\\Rightarrow f(x)=20-7x^2+(20-4x+5x^2)\\\Rightarrow f(x)=-2x^2-4x+40[/tex]