Make sure you answer this 100% correctly

2x - 20 = 32 20 - 3x = 8 6x - 8 = 16 -13 - 3x = -10

The sixth grade art students are making a mosaic using tiles in the shape of right triangles.each tile has leg measures of 3 centimeters and 5 centimeters.i f there are 200 tiles in the mosaic what is the area of the mosaic.

What situation is an example of an observational study