Respuesta :

The answer i got was c because the letter x goes into each of them because they each have a x in them. It would be B but 3 doesnt go into 28. 

Answer:

The correct option is C.

Step-by-step explanation:

The given expression is

[tex]21x-18x+28xy[/tex]

The factors of each term are

[tex]21x=3\times 7\times x[/tex]

[tex]18x=3\times 6\times x[/tex]

[tex]28xy=2\times 2\times 7\times x\times y[/tex]

The common factor is x.

[tex]G.C.F.=x[/tex]

Therefore correct option is C.