Answer:
![(-1)/(5)m-(4)/(5)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wp4xjyzkb9jybrwezpdr57hbciu6zj63to.png)
Explanation:
You are given:
![(2)/(5)m-(4)/(5)-(3)/(5)m](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4wq6h8869amgvw305svcnbp9blubiq0pio.png)
Reorder using commutative property (putting like terms together):
![(2)/(5)m-(3)/(5)m-(4)/(5)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7w9z7gv0nymj2xe3p0wao5mx93cnfcq7rg.png)
Now we are going to bring down the -4/5 (there is nothing to do there).
(2/5)m and -(3/5)m have the same denominator all we have to do is figure out what is 2-3 which is -1
![(-1)/(5)m-(4)/(5)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wp4xjyzkb9jybrwezpdr57hbciu6zj63to.png)