[tex]\huge\text{Hey there!}[/tex]
[tex]\large\boxed{\mathsf{y^2 + 66 + x - 12}}\\\large\boxed{\mathsf{= 4^2 + 66 + 6 - 12}}\\\large\boxed{\mathsf{= 16 + 66 + 6 - 12}}\\\large\boxed{\mathsf{= 82 + 6 - 12}}\\\large\boxed{\mathsf{= 88 - 12}}\\\large\boxed{\mathsf{= 76}}\\\\\\\huge\boxed{\text{Therefore, your answer: \textsf{76}}}\huge\checkmark[/tex]
[tex]\huge\text{Good luck on your assignment \& enjoy your day!}[/tex]