Well, you need write the system of equation:
If we call "P" to quantity of pencils and we call "N" to quantity of notebooks, the total quantity of articles in an equation is:
P+N=19
And the total money that Joanna spent in an equation is:
$1.46*P+$2.41*N=$32.49
Now you only need to solve that system.
Good luck!
M.