Im not sure how to do this "y=x+0.5

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Which of the following shows the length of the third side, in inches, of the triangle below

Amap has a scale of 3.5 inches = 20 kilometers. if the distance between two cities on the map is 4.9 inches, what is the actual distance between the two cities?