Which expression represents 81 decreased by an unknown number

On a architect's drawing of a house, 1 inche representa 1.5

Gail is making costumes for a school play. each rabbit costume needs one and one half yards of white fur fabric, a yard of blue striped fabric, and a quarter of a yard of pink felt for the ears. g? ail needs to make eight rabbit man yards will she need, for the white fur fabric, blue striped fabric, and pink felt?

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.