Yes, the student's theory is correct, because the survey shows that the seventh graders spend more time playing games on the weekend than the eighth graders.
Not sure about the first one but the second one is option c (or -3). You just have to factor and find the solutions (so it would be -7 and 4 and then u just add them)
For question 39 the answer is c
Answer:

And then we can use for example the first point
to find the intercept:


So then the linear model for this case should be:

Step-by-step explanation:
For this case we want to find a linear model given by:

Where r = represent the number of readers , t= years after 2000
m = the slope for the model and b the intercept
For this case we can define the following points from the data given:
4 years after 2000
14 years after 2000
We can find the slope with the following formula:

And then we can use for example the first point
to find the intercept:


So then the linear model for this case should be:

Answer:
x+5=12
x+7=15
x+ 1/2=1
x+1/3=1
4(x+1)= 8
1.5+x=3
Olivia is 5 years older than Nicole. The sum of their ages is 35. How old is each girl?
Step-by-step explanation:
how this helps!