A botanical garden has plans to construct a walkway that is x meters wide around a rectangular rose garden measuring m meters by n meters. Altogether, the garden and walkway will cover an area of A square meters. Which of the following statements are constraints in this problem? Select all statements that are true.
a)The width of the walkway, x, must be a positive number.
b)The length of the rectangular rose garden, m, must be greater than or equal to x.
c)The area of the rectangular rose garden, m×n, must be equal to A.
d)The area of the garden plus the area of the walkway must be equal to the total area of the garden and walkway.