What is the property of 7+x+y+4

Asquare picture with sides of 32 inches is to be mounted on a square mat with sides of 52 inches. find the area of the mat that will remain uncovered by the picture.

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line

I'm a polygon i have no parallel lines i am formed 3 line segments i have one right angle two of my angles are angles what am i