what is -3--19

this post might help you

http://web2.0calc.com/questions/it-just-doesn-t-make-sense-to-me#r2

$${\mathtt{\,-\,}}{\mathtt{3}}{\mathtt{\,\small\textbf+\,}}{\mathtt{19}} = {\mathtt{16}}$$

.

Remember that a - (-b) = a + b

 

We get: -3 - (-19) = -3 + 19 = 19 - 3 = 16