In this CTF we are given with a image math.jpg. So we will use strings command to get the strings associated with the image.
Fire strings math.jpg in the terminal.



We can find a string which gives a hint to find our flag.

CTFlearn{I_Like_Math_x_y}
where x and y are the solution to these equations:
3x + 5y = 31
7x + 9y = 59

So we will find the solutions of the above both equations and put them in the flag.

After solving the above equations we will get the following solutions:

x = 2
y = 5

Flag is : CTFlearn{I_Like_Math_2_5}