Estimate the area of a circle with a radius of 21 meters. Use 22/7 for pie.

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Prove that 16^4-2^13-4^5 is divisible by 11.

If each bricks costs and he can only buy one brick how much will it cost him to get the material to put around the outside of his garden?