Answer:
4d
Step-by-step explanation:
i think any variable alone with no coefficient equals one
so this problem is like adding the terms 3d + 1d
so 1+3=4
and you use the variable d at the end
therefore the answer would be 4d
hope this helped<3
3d+d this means 3d+1d because any variable without a coefficient is 1
which means
3d+1d
=4d
hope this helps!!!
