A landscape designer has to design a rectangular pad of concrete at the centre of a rock garden. The lenght must be less than or equal to twice the width; the perimeter must be less than or equal to 40 m; and the area must be greater than or equal to 60 m².
1.)Write as system of inequalities to represent the constraints in this problem situation.
x=width y=length
y<=2x
2(x+y)<=40
xy>=60