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.
(f+g-k)(x) means to add the equations f(x) and g(x) then subtract k(x)
2x^2 + 3x + 4x - 9 = 2x^2 +7x -9
2x^2 + 7x - 9 - x^2 -7x = x^2 -9
The answer is : x^2 - 9
9,500 just add the 0 always add 0 if you multiply by 10. 00 for 100 and 000 for 1000
Answer:
123 tons
Step-by-step explanation:
1) Convert 12 1/3 tons to a decimal - 12.3
2) multiply 12.3 by 10 - 123 tons