Solution 1.1:1c

The brackets indicate in which order the expression is to be calculated, and we start by calculating the inner bracket.

\displaystyle 3-(7-\bbox[#FFEEAA;,1.5pt]{\,(4+6)\,}-5) = 3-(7-\bbox[#FFEEAA;,1.5pt]{\,10\,}-5).

Then, we calculate the next bracket.

\displaystyle \phantom{3-(7-\bbox[#FFEEAA;,1.5pt]{\,(4+6)\,}-5)}{}=3-\firstcbox{#FFEEAA;}{\,(7-10-5)\,}{(-8)}

\displaystyle \phantom{3-(7-\bbox[#FFEEAA;,1.5pt]{\,(4+6)\,}-5)}{}=3-\secondcbox{#FFEEAA;}{\,(7-10-5)\,}{(-8)}

and when we remove the brackets in "\displaystyle {}-(-8)" we get "\displaystyle {}+8",

\displaystyle \phantom{3-(7-\bbox[#FFEEAA;,1.5pt]{\,(4+6)\,}-5)}{}=3+8

\displaystyle \phantom{3-(7-\bbox[#FFEEAA;,1.5pt]{\,(4+6)\,}-5)}{}=11.