Let's carefully solve the given problem step-by-step:
First, we are asked to compute the sum of [tex]\(999999\)[/tex] and [tex]\(1\)[/tex].
a) [tex]\(999999 + 1 = 1000000\)[/tex]
So, the sum of [tex]\(999999\)[/tex] and [tex]\(1\)[/tex] is [tex]\(1000000\)[/tex].
The problem also provides another value, which is [tex]\(-105\)[/tex].
Thus, filling in the blanks, we get:
[tex]\[ \text{a)} \quad 999999 + 1 = 1000000 \qquad -105 \][/tex]