Aresearch group interested in understanding the effect of listening to classical music on learning mathematics conducted a study. one hundred students were randomly assigned to one of two groups. the first group listened to classical music as they learned a new lesson. the second group learned the same lesson with no music playing. both groups were tested on the new material to determine how much they learned. the results for the two groups were compared. what kind of study is this?
a). this is an observational study because students were randomly assigned to groups.
b).this is an observational study because a treatment was applied to both groups.
c).this is an experiment because a treatment was applied to a group.
d).this is an experiment because students were able to choose which group to join.

when rotating a figure 180 degrees, imagine that you are able to take the figure and turn it clockwise or counterclockwise around a center point. to rotate a figure 180 degrees, you will need to apply the rule (x, y) → (-x, -y). start by using a coordinate grid with coordinates for each vertex of the figure. the center point of the coordinate grid is located at (0, 0), which is what you will rotate the figure around. write down the original coordinates of the shape you are going to rotate. then, apply the rule. for example, coordinate (1, 2) becomes (-1, -2). another example would be, coordinate (-4, -2) becoming (4, 2). after you change each original coordinate to the rotated coordinate, you will draw your new figure.

step-by-step explanation:

-3n+2+5n-7=

2n+2-7=

2n-5 (d)

the answer is b because i did this question and aced the test

math ya dumb fu*k

step-by-step explanation: