The base and height will each be doubled. Will the area also be doubled? Explain how you know.

No, the area would not be doubled. Remember, the equation we are using is b*h=a (base*height=area) or bh=a and we are doubling both the base and the height, this gives us the equation 2b*2h=a, keep in mind that this time the area can be anything. Now, from this equation, if we multiple the 2b and 2h, we get 4bh, which is the same as saying 4*the area (which is b*h)

True the variable in the expression is y