etermine whether the given description corresponds to an observational study or an experiment. In a study of 444 women with a particular​ disease, the subjects were photographed daily. Does the given description correspond to an observational study or an​ experiment?

observational study

Explanation:

The above is an example of observational study. An observational study merely observes and takes note, it does not try to interfere or intervene with the sample by deciding who would be exposed or not exposed to a certain explanatory variable(such as a disease). On the other hand, the experimental study divide up samples into groups, having the experimental group and the control group. This way the researcher interfers with the sample: The experimental group being the group exposed to the independent/explanatory variable while the other/control group is not.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.