Find the distance cd rounded to the nearest tenth. c=(7,-4) d=(-7,-5)

The equation for distance is the sqrt of (x-x)^2+(y-y)^2.
C(7,-4) D(-7,-5) 7 becomes x1 and -4 becomes y1. -7 is now x2 and -5 is y2. Plug them in, the order doesn't matter.
(-7-7)^2+(-5+4)^2
(-14)^2+(-1)^2
196+1
sqrt of 197
or 
Rad 197

Answerequatorial guinea,gabon, and western sahara;