Answer:
Lori's age is 15 years old and Michelle's age is 5 years old now
Step-by-step explanation:
Let
x-----> Lori's age
y ----> Michelle's age
we know that
-----> equation A
----> equation B
substitute equation A in equation B and solve for y
Find the value of x

therefore
Lori's age is 15 years old and Michelle's age is 5 years old now
Answer:
Option C
The student's conclusion is correct because the solution to the system of equations
and
is 
Step-by-step explanation:
Let
x------> the cost of each burger
y-----> the cost of each sandwich
we know that
-----> equation A
----> equation B
Solve the system of equations
Multiply the equation B by 
----->
------> equation C
Adds equation A and equation C

Substitute the value of x in the equation B



The solution of the system of equations is the point 
so
The price of each burger is 
The price of each sandwich is 
Answer:
Here we will use the relationships:



And a number:

is between 0 and 1 if a is positive and larger than 1, and n is negative.
if a is positive and 0 < a < 1, then we need to have n positive such that:
0 < a^n < 1
A) 
This is between zero and 1,
B) 
This is greater than 1, because the exponent is positive.
C) 
Because a is smaller than 1, and the exponent is positive, then the expression is between 0 and 1.
D) 
The exponent is negative (and pair) then the expression is between 0 and 1.
Remember that when the exponent is pair, we always have that:
(-N)^m = (N)^m
So (-7)^-2 = 7^-2
Answer:
Part a
For the given study, the explanatory variable or independent variable is given as regularity or frequency of exercise. This variable is classify as categorical variable because variable is divided into two categories such as whether participant exercise 5 or more days a week or not.
Part b
For the given study, the response variable or dependent variable is given as frequency of colds. This variable is classified as quantitative variable because we measure the quantities or frequency of number of colds.
Part c
A confounding variable for this research study is given as incidence of upper respiratory tract infections that provides an alternative explanation for the lower frequency of colds among those who exercised 5 or more days per week, compared to those who were largely sedentary. This confounding variable is categorical in nature.
I am pretty sure that B is the answer