Answer:
[tex](ab)(x)[/tex]
Step-by-step explanation:
The complete question in the attached figure
we have
[tex]a(x)=2x-4\\b(x)=x+2[/tex]
we know that
(ab)(x) is equal to the product of a(x) and b(x)
so
[tex](ab)(x)=(2x-4)(x+2)[/tex]
Applying distributive property
[tex](ab)(x)=2x(x)+2x(2)-4(x)-4(2)[/tex]
[tex](ab)(x)=2x^2+4x-4x-8[/tex]
[tex](ab)(x)=2x^2-8[/tex]
This is a quadratic equation
The other expressions not produce a quadratic equation
