because we have to find the total cost of one pound of the mixture, therefore first we will calculate the total cost of cashews and Peanuts and than we will divide the total cost by the total weight.
Find the minimum point on the parabola, and take the x component of the coordinate. Then, put that number into this equation: x = (whatever the number was) so in this case the axis (or line) of symmetry is x = 1