Maurizio

It would be useful to everybody, online press, users, and even Apple, to use the correct language.
Notes do not solve equations, it computes expressions. 
An equation is something like x^2-1= 0, and solving it means finding the values of the 'variables' that make the equality true.
Computing an expression is executing a algorithm writter as a mathematicak expression: 3*5-2 means multiply 3 by 5, add 2 and tell us the results.
The two things are wildly different, with different use cases, and very different complexity.

Maurizio