Which algebraic expression means “four less than three times a number”?
A. 4 minus n cubed
B. 3 n minus 4
C. 4 minus 3 n
D. n cubed minus 4

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?