According to the National Sleep Foundation, teenagers need about 9 hours of sleep each night to function at thelr best. Unfortunately, many teens do not get nearly this amount. Two samples of 100 teenagers were asked about the
average number of hours they sleep each school night. The results are recorded in the table below.
<4 4-6 6-8 8-10 10+
Sample #12
939
44. Select all that apply
6
Sample #2 1 12
34
48
5
5
Based on the results of the survey, which of the following inferences are valid?
Adults need less sleep than teenagers.
About half of teenagers get less than 8 hours of sleep each school night.
At least 10% of teenagers have sleep-related issues such as depression, insomnia, and drowsiness during the day.
Half of teenagers get the recommended 9
1
hours of sleep each school night.
More than 90% of teenagers get between 4 and 10 hours of sleep each school night.

a.   we have two

lines:   y = 4-x   and  

y = 8-x^-1

given two simultaneous equations that are both to be

true, then the solution is the points where the lines cross. the intersection is

where the two equations are equal. therefore the solution that works for both

equations is when

4-x = 8-x^-1

this is where the two lines will cross and that is the

common point that satisfies both equations.

b.   4-x = 8-x^-1

  x           4-x       8-x^-1

-3           7        

8.33

-2           6         8.5

-1           5         9

  0           4        

-

  1           3        

7

  2           2        

7.5

  3           1         7.67

the table shows that none of the x values from -3 to 3 is

the solution because in no case does

4-x = 8-x^-1

to find the solution we need to rearrange the equation to

find for x:

4-x = 8-x^-1

multiply both sides with x:

4x-x^2 = 8x-1

x^2+4x-1=0

x= -4.236, 0.236

therefore there are two points that satisfies the

equation.

find y:  

x=-4.236

y = 4-x   = 4 – (-4.236)

= 8.236

y = 8-x^-1 =   .236)^-1

= 8.236

x=0.236

  y = 4-x   = 4 – (0.236) = 3.764

y = 8-x^-1 =   8-(0.236)^-1

= 3.764

thus the two lines cross at 2 points:

(-4.236, 8.236) & (0.236, 3.764)

c.   to solve

graphically the equation 4-x = 8-x^-1

we would graph both lines: y = 4-x   and   y

= 8-x^-1

the point on the graph where the lines cross is the

solution to the system of equations.

just graph the points on part b on a cartesian coordinate

system and extend the two lines.   the

solution is, as stated, the point where the two lines cross on the graph.

step-by-step explanation:

mark brainliest!

wth is with the little mtn top and what are you talking about like fix your words and accually make sence with them and i like was in a completly different question like three times like it seems like your ilitteret

i think it would be c

mark brainliest if im right

step-by-step explanation: