We need to find the expression that is equivalent to:
Let's analyze our options:
Option a:
in this option, we have that 3 is an exponent, which is different from what we are looking for because, in 3y, the 3 is the coefficient of the expression, not the exponent. Thus, option a is discarded.
Option b:
In this case, the 3 and the "y" are separate terms, and since 3 is a number and "y" is a variable, we cannot add them because they are not like terms. So 3+y is not equal to 3y.
Option c:
In this option, all of the terms are variables (all of the terms are "y") which means in this case, unlike the last case, we can add the terms:
Thus, this is the correct option because y+y+y is equal to 3y.
Answer:
c. y+y+y