1st you combine like terms so subtract 7y and 3y and you get 4y. So this is the final answer: 4y+4b.
Answer:
c. observational study
Step-by-step explanation:
<em>Researchers compare the rates of autism for children who did and did not receive the standard measles-mumps-rubella vaccine, to see if the vaccine might be responsible for autism in some children.</em>
This study design in the above scenario is observational study because the researcher are obviously observing whether the vaccine is affecting the children. Note that Observational study is like experiment which attempts to understand the cause and effect relationships on a subject.
In order to find out what 36x + 9 is equivalent to,, we must factor out 9 from the expression. Once we do this you will find that this expression is equivalent to 9(4x + 1),, or option E.
Next we will look at the expression 9(4x -1). In order for us to find out the equivalent to this expression,, we must first multiply each term in the parenthesis by 9.
9 × 4x - 9
Now calculate the product
36x - 9
This means that the equivalent for this expression is 36x - 9,, or option A.
Lastly,, we will look at the final expression given which is 4(9x + 2). The first step for finding the equivalent of this expression is to multiply the numbers in the first parenthesis together.
(36x) + (4 × 2)
Now multiply the numbers in the second parenthesis together.
(36x) + 8
Remove the parenthesis
36x + 8
Now factor out 4 from the expression to get your final answer.
4(9x + 2)
This means that the last expression is equivalent to 4(9x + 2),, or option C.
Let me know if you have any further questions
:)
Yes, the cost is proportional to the number of water bottles sold. 6 water bottles/$4.00 = 1.5 and 15 water bottles/$10.00 = 1.5.
