Answer:
B. Larger sample size and lower confidence level
Step-by-step explanation:
The margin of error of a confidence interval is given by the following formula:

In which
is the standard deviation of the population and n is the size of the sample.
z is related to the confidence level. The higher the confidence level, the higher the value of Z.
So, the margin of error is direct proportion to the confidence level and inverse proportional to the sample size.
We want to decrease the margin of error.
So the correct answer is:
B. Larger sample size and lower confidence level
Answer:

Step-by-step explanation:
The question is

collect like terms

Answer:
C. -7x^2 - 28
Step-by-step explanation:
Firstly simplify the bracket before doing anything;
4x(3x - 7) = 12x^2 - 28x
then go back to the question and substitute the expression(12x^2 - 28x) on the bracket and then work out the question;
12x^2 - 28x -19x^2...then group the values with the same exponent of x,
(12x^2 - 19x^2) - 28x
; -7x^2 - 28x
Answer:
(5x+1)(x+7)
Step-by-step explanation:
4x^2+26x+6+x^2+10x
5x^2+36x+7
(5x+1)(x+7)
Prove
5x*x + 5x*7 + 1*x + 1*7
= 5x^2 + 35x + x + 7
= 5x^2 + 36x + 7
3x+4=x+2
2x+4=2
2x=-2
-2/2
X=-1
Y=-1+2
Y= 1
Solution= (-1,1)