Answer:
The number of pages that Polina read was 90 and the number of pages that Marcus read was 18
Step-by-step explanation:
Let
x -----> number of pages that Polina read
y ----> number of pages that Marcus read
we know that
x+y=108 ----> equation A
x=5y -----> equation B
substitute equation B in equation A and solve for y

Find the value of x

therefore
The number of pages that Polina read was 90 and the number of pages that Marcus read was 18
Answer:
D. 4
Step-by-step explanation:

If I did my math correctly I believe your answer will be C. :)
Answer: (0.8115, 0.8645)
Step-by-step explanation:
Let p be the proportion of people who leave one space after a period.
Given: Sample size : n= 525
Number of people responded that they leave one space. =440
i.e. sample proportion: 
z-score for 90% confidence level : 1.645
Formula to find the confidence interval :


Hence, a 90% confidence interval for the proportion of people who leave one space after a period: (0.8115, 0.8645)
Answer:
x=1
Step-by-step explanation:
1. Complete the square on the right side of the equation.
5
(
x
−
1
)2
−
18
2. Use the vertex form, y
=
a
(
x
−
h
)
2
+
k
, to determine the values of a
, h
, and k
.
a=
5
h
=
1
k
=
−
18
3. Since the value of a is positive, the parabola opens up.
Opens Up
4. Find the vertex (
h
,
k
)
.
(
1
,
−
18
)
5. Find p
, the distance from the vertex to the focus.
1
/20
6. Find the focus.
7. (
1
,
−
359/
20
)
8. Find the axis of symmetry by finding the line that passes through the vertex and the focus.
ANSWER: x
=
1