Is a square a rhombus ? tell me in great details

The depth of a lake at a certain point, wich is a function of the distance of that point from shore, is 30 feet.

Afurniture manufacturer produces chairs and sofas. each chair requires 10 yards of fabric, and each sofa requires 20 yards of fabric. the manufacturer has 300 yards of fabric available. to fulfill orders, the number of sofas must be at least twice the number of chairs. let x be the number of chairs and y the number of sofas. which inequalities are described in the problem? check all of the boxes that apply

One positive number is 9 more than twice another. if their product is 95, find the numbers