Lisa -A big part of advanced algebra is being able to picture in your mind (or a sketch on paper) what the problem is asking.For this problem, you have a rectangular garden that has a perimeter of 150 feet. You might want to draw what I'm describing on paper:One side has a ten foot opening and let's say this side has length "x" feet. The side opposite the side with the opening must be (x + 10) feet. Now the other two sides of this rectangular garden are equal, so let them both equal y. Whew! Now, let's put that all into our first equation:150 = x + (x+10) + y + y, or to simplify140 = 2x + 2yNow maximize the area in the garden which is:A = x * y. But, we need to get this equation in one variable (x or y), so use the first equation and solve for x:If 140 = 2x + 2y, then x = 70 - y. Now substitute this into A = x * y.A = (70-y) * y = 70y - y^2.This is the quadratic you want to maximize. This is simply a parabola, so find the vertex and you will have found the maximum.