31/3 × 2 1/4 i dont know what it is

You are making a battery for a science project. you have copper wire for your first electrode. you need to choose a conductor, a second electrode, and a device to plug into your battery. you have already chosen a lemon conductor. complete each statement below about the options that include a lemon conductor.

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

How is working backward similar to solving an equation?