A gardener wants to create a triangular garden in the shape of a right triangle with shortest side length x-2y ft. and the middle length side x+6y ft. What is the area of the garden? multiply this out and express in simpliest correct mathematical form including units

Area = 1/2)base x height

= (1/2)(x-2y)(x+6y)

Now follow the instructions in your problem, that is,
multiply this out and express in simplest form