Answer:
14x-85
Step-by-step explanation:
The area of the shaded region is
[tex](x + 6)(x - 6) - {(x - 7)}^{2} [/tex]
which if you use the identities to expand it gives you
[tex] {x}^{2} - 36 - {x}^{2} + 14x - 49[/tex]
This then reduces to be
[tex]14x - 85[/tex]
