$ sudo apt-get update
$ sudo apt-get install libcufftw7.5 

libcufftw7.5 is installed in your system.

Make ensure the libcufftw7.5 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libcufftw7.5 *

You will get with libcufftw7.5 package name, version, architecture and description in a table

libcufftw7.5 package basic information: