we know that
The sum of the lengths of any two sides of a triangle is greater than the length of the third side (Triangle Inequality Theorem)
so
inequality 1
[tex](2+7) \ \textgreater \ x \\ 9 \ \textgreater \ x \\ x \ \textless \ 9 in [/tex]
inequality 2
[tex](x+2) \ \textgreater \ 7 \\ x \ \textgreater \ 7-2 \\ x \ \textgreater \ 5 in [/tex]
the answer is
[tex]5 in \ \textless \ x \ \textless \ 9 in[/tex]
