Why are there two unit rates for all ratio relationships, like the one shown here?

Wrote and expression for the difference of p and 4

The following hormone had their receptors in the cell membrane except a-insulin b-tsh c-gh d- cortisol

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.