Answer:
The margin of error for a sample size of 250 is 6
Step-by-step explanation:
The margin of error is given as
1/square root of the sample size
Thus, margin of error for a sapless size of 250 is
1/√250
= 1/15. 811
= 6
I'm assuming all of (x^2+9) is in the denominator. If that assumption is correct, then,
One possible answer is 
Another possible answer is 
There are many ways to do this. The idea is that when we have f( g(x) ), we basically replace every x in f(x) with g(x)
So in the first example above, we would have

In that third step, g(x) was replaced with x^2+9 since g(x) = x^2+9.
Similar steps will happen with the second example as well (when g(x) = x^2)
Answer:4600
Step-by-step explanation:
15% of 4000
15/100 x 4000
(15x4000) ➗ 100
60000 ➗ 100=600
4000+15% of 4000
4000+600=4600
I will show you how to do #5:
a). -20 + 2(n-1) Original Expression
-20 +2n - 2 Distributive Property
-22 + n Combine Like Terms
Final Expression: -22 + n
b). 1.5 + (-2.5)(n -1) Original Expression
1.5 + -2.5n + 2.5 Distributive Property
4 - 2.5n Combine Like Terms
Final Expression: 4 - 2.5n