Given a pair parallel lines cut by a transversal same interior angles are supplementary?

Find dy/dx using implicit differentiation ln(20+e^xy)=y

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Using the side-splitter theorem, daniel wrote a proportion for the segment formed by luke segment de. what is ec?