An observation study is where nothing changes and you record what is seen. An experimental study you have a control group and a testable group.
The answer would be: .C. The groups in an experiment are chosen at random, but not in an observational study.
First subtract the 20 from both sides so it is 3x=2x+4 thens ubtract the 2 so x equals 4
Answer is in the attachment below.
Answer
1/4 × 6 × (5a) = 12
15a=12
a= 4/5
Step-by-step explanation:
