What is the Magnetic Field at Point O?

[TuanTran]

Homework Statement

Homework Equations

Magnetic Field of a Current Loop
The Field of a Long Straight Wire

The Attempt at a Solution

Sorry ! I'm so stupid that i couldn't figure a way to solve this exercise.
I don't know how to start with those two equations.
Please help me !

 

[TuanTran]

Sorry for the image : https://imgur.com/a/1pL3o