In a state legislature, there were 119 more members in the house of representatives than in the senate. if there were m members in the senate, write an expression to represent the total members in the state legislature

We know the senate has m members. We will have an equation itself to find how many members are in the house of representatives. 
There are 119 more than the senate, which is m:
119+m
Now we are looking for the total members in the state legislature. We need the senate and house of representatives together.
m+119+m
We can simplify that more because there are two m's.
2m+119 would be the expression for the total members in the state legislature.