What is 3x-2y when x=4 and why equals 2

Which system of linear inequalities is represented by the graph? !

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.

Which value is not a solution of 8x^3 – 1 = 0