Xb+12-1/3b-13 what is the value of x

What is the product of the radical expression. (7-2square root) (8+2 square root)

Icould really use some with this question.

The rectangle shown has a perimeter of 108 cm and the given area. its length is 6 more than five times its width. write and solve a system of equations to find the dimensions of the rectangle.