Let x equal the ice thickness. An equality that represents a safe ice thickness for walkability is:
x ≥ 4 inches
(Plus the graph)
Step-by-step explanation:
Defining a variable just means you let any letter or symbol take the place of something. But you have to specifically say what is what in order for it to be clear.
So I defined "x" as the variable to represent the ice's thickness. And since we want an inequality for all the safe thicknesses, we could say that "x" must be greater than or equal to 4 inches thick in order to safely walk on it.
Lastly, you'd graph it with a solid point on 4 with the arrow going to the right.
The surface area of a sphere is 4r^2pi, so dividing 100 by 4pi gives a result of 25/pi. Taking the square root and rationalizing the denominator, we have 5sqrt(pi)/pi as the radius of the sphere.