Rewriting the expression:
![5a^5b^4](https://tex.z-dn.net/?f=5a%5E5b%5E4)
We have two terms inside the expression; the
![a^5](https://tex.z-dn.net/?f=a%5E5)
and
![b^4](https://tex.z-dn.net/?f=b%5E4)
Option one:
![a^5b^4](https://tex.z-dn.net/?f=a%5E5b%5E4)
⇒ this is a like terms since it also has
![a^5](https://tex.z-dn.net/?f=a%5E5%20)
and
![b^4](https://tex.z-dn.net/?f=b%5E4)
Option two:
![5a^4b^5](https://tex.z-dn.net/?f=5a%5E4b%5E5)
⇒ This expression has
![a^4](https://tex.z-dn.net/?f=a%5E4)
and
![b^5](https://tex.z-dn.net/?f=b%5E5)
which aren't the same with the original expression.
Option three:
![-2a^5](https://tex.z-dn.net/?f=-2a%5E5)
⇒ This expression only has the term
![a^5](https://tex.z-dn.net/?f=a%5E5)
, so it isn't a like term with the original expression.
Option four:
![-a^5b^4](https://tex.z-dn.net/?f=-a%5E5b%5E4)
⇒ This expression has two terms,
![a^5](https://tex.z-dn.net/?f=a%5E5)
and
![b^4](https://tex.z-dn.net/?f=b%5E4)
which are the same terms with the original expression.
Option five:
![9a^5b^4](https://tex.z-dn.net/?f=9a%5E5b%5E4)
⇒ This expression has two terms,
![a^5](https://tex.z-dn.net/?f=a%5E5)
and
![b^4](https://tex.z-dn.net/?f=b%5E4)
which are the same with the original expression.
Option six:
![2a^5b^5](https://tex.z-dn.net/?f=2a%5E5b%5E5)
⇒ This expression has two terms,
![a^5](https://tex.z-dn.net/?f=a%5E5)
and
![b^5](https://tex.z-dn.net/?f=b%5E5)
which aren't exactly the same terms with the original expression.
Option seven:
![6b^4](https://tex.z-dn.net/?f=6b%5E4)
⇒ This expression only has one term, which isn't exactly the same with the original expression.
Answers: Option 1, 4 , and 5