Answer:
-6y^3+7y^2-2
Step-by-step explanation:
(-2y^3+2y^2-9)+(-4y^3+5y^2+7)
-2y^3-4y^3+2y^2+5y^2-9+7
-6y^3+7y^2-2
1) A. Biased because the population could be uneven. Too many of one ethnicity, too many of one gender, etc.
2) I believe this one is C. because there are not enough people. You need to survey the majority of parents instead of a selected few.
3) There are 80 green marbles per 500, therefore calculate the percentage.

or

percent. Multiply

percent or

times 25. It gives you

.
4) This one is a probability thing too. For every 500 batteries, there are 3 that are defective, therefore,

.

5) Yet another one. Add up all the nuts and you get

. The chance of getting a cashew from these

is:

.
Therefore:
For the answer to the question above, If you've noticed, the statement mentioned "a number". Let's assign x to be the number. The first statement is twice a number (2x). Then, decreased by the quotient of that number and 2 (-x/2). Lastly, the statement at least 12 is written as >12.
So the answer is
2x - (x/2) >12
Answer:
30
Step-by-step explanation: