Final answer:
The equivalent expression when combining like terms is ⅔a - ⅖.
Step-by-step explanation:
To create an equivalent expression by combining like terms, we look at the coefficients of the variable 'a' and add them together. Here we have terms with 'a' which involve fractions with different denominators. To combine these, we find a common denominator, which in this case would be 6, because 6 is the least common multiple (LCM) of 3 and 6.
So, the expression will look like this:
- ⅓a + ⅔a = -⅔(2a) + ⅓(3a)
This gives us:
(-⅔*2 + ⅓*3)a = (-⅖ +⅒)a
When we combine the fractions, we get:
(-⅖ + ⅒) = ⅔
So the expression simplifies to:
⅔a - ⅖