Question 781147
A number, c.

5c-18....?
5(c-18...)...?
Your description is ambiguous.


Your phrasing might intend, 5c-18-4c; or the phrasing might intend being, 5(c-18-4c); or it might mean, 5(c-18)-4c, or maybe it was intended to mean something else.  Too many possibilities.


State the description precisely and the problem can be translated into clear symbolism.