The expression is 

Additive inverse of – 34 is 34.

To subtract –3 4, add 34.

Now, the expression becomes .

To add integers first draw a number line diagram.

\
• Start from zero move 78 units right to reach 78.
\
• Then move 34 units right show the addition of 34.
\
• Find the final position on the number line.
\

The difference of is 112.

The difference of is 112.