Is this a leaf of an ash tree?

Here are another 2 leaf photos that are quite similar but are from different trees.
Can anyone help identify them? These look like ash tree leaves but I want to be sure.
Thank you.

 

I think the left hand picture is a Carya. The right hand picture could be a Fraxinus, possibly F. pennsylvanica?

 

Look at the arrangement of the leaves on a branch. Ash leaves are opposite while hickory leaves are alternate.

 

Left hand leaf may be an elder Sambucus. A photo of a branch with several leaves would help.

Right hand leaf is Fraxinus excelsior.

 

I thought Fraxinus excelsior leaves had a narrowly pointed tip. They also have more leaflets usually and the ones in the photo are very rounded compared to the Ash leaves outside my office window.
Could be Sambucus but again, its the narrowly pointed leaf tips that stand out. Not a European species though right? Maybe Sambucus caerulea?

 

Showing additional parts like twigs, buds or fruits would give you more certain answers.

 

Unfortunately these photos were taken 2 years ago. So I cant provide additional parts like like twigs, buds or fruits.