Find Each Sum Or Difference. 1) 12 + (- 3)
2) -7 + 4
3) -8 + (- 6)
4) -42 + 15
5) 32 - ( - 8)
6) -18 - 12
7) -15 - (-14)
8) -76 - 5

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?