Helen is trying to prove the difference formula for cosine. She has started her proof as shown above. What property would she need to use for the next step in the proof?

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Cameron made 1 loaf of bread. his family ate 4/6 of the loaf of bread. how much of the loaf of bread remains? /

What is the value of x? enter your answer in the box. x = two intersecting tangents that form an angle of x degrees and an angle of 134 degrees.