We have the expression:
[tex]10a-7+9a[/tex]We can simplify it by grouping the similar terms 10a and 9a:
[tex]\begin{gathered} 10a-7+9a \\ 10a+9a-7 \\ (10+9)a-7 \\ 19a-7 \end{gathered}[/tex]When a=2, we can replace a with the value 2 and calculate:
[tex]\begin{gathered} 19a-7 \\ 19(2)-7 \\ 38-7 \\ 31 \end{gathered}[/tex]Answer: The simplified expression is 19a-7.
The result of the expression when a=2 is 31.