which of the following are monomials?
check all that apply.
A.19
B.y
C.x^9+y^9
D.x^23
E.13^9+12
F.2x+2
check all that apply.
A.19
B.y
C.x^9+y^9
D.x^23
E.13^9+12
F.2x+2