A -1 or 0.86 B 1or0.86
C 1or -0.86
D -1or -0.86

I know the answer is A but i need the working plz...

If the scale factor between two circles is 2x/5y what is the ratio of their areas?

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid in order to get a 40% solution of acid?

If you were constructing a triangular frame, and you had wood in the length of 4inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood? yes or no. explain your mathematical thinking