A) The question would be "Does cell phone use time correlate to brain cancer?". The population is all cell phone users. The sample is the 469 people with brain cancer, and the 422 healthy people.
B) This sample size may not portray the entire population of users because the positive results may have been fabricated by factors other than cell phone use. You would have to figure out the population size and determine the correct sample size.
C) This study may not portray cell phone use correlation over a large population efficiently because of the sample size and the predetermined conclusion that cell phone use causes cancer.
Answer:
A.( 3m+28)/4
Step-by-step explanation:
So basically since it is addition we just add 9 to -2 to get 7. So then the equation becomes (3m/4)+7. Then we will multiply 7 by 4 to get common denominator so it will be (3m+(7*4))/4 which is (3m+28)/4.
Solve either equation for either variable. Since the second one has y on its own, the easiest choice is to solve that for y.
-5x + y = 13 ⇒ y = 5x + 13
Now substitute this into the other equation to eliminate y and rewrite it entirely in terms of x :
-3x + 3y = 3 ⇒ -3x + 3 (5x + 13) = 3
Simplify and solve for x :
-3x + 15x + 39 = 3
12x = -36
x = -3
Substitute this into either original equation to solve for y. Plugging x = -3 into the first equation would give
-3 (-3) + 3y = 3
9 + 3y = 3
3y = -6
y = -2
So the solution to the system of equations is (x, y) = (-3, -2).
Answer: Step 1: Reverse the signs of
expression.
Step 2: Removing parenthesis
Step 3: Grouping like terms
Step 4: Combing like terms
Step 5: Writing the final expression in standard form
Step-by-step explanation: First expression :
Second expression :
.
We need to subtract
from
.
Step 1: Reverse the signs of
expression.

Step 2: Removing parenthesis

Step 3: Grouping like terms
![[-3x^3) + (-6x^3)] + [4x + 2x] + [(-7) + (-3)] + [5x^2]](https://tex.z-dn.net/?f=%5B-3x%5E3%29%20%2B%20%28-6x%5E3%29%5D%20%2B%20%5B4x%20%2B%202x%5D%20%2B%20%5B%28-7%29%20%2B%20%28-3%29%5D%20%2B%20%5B5x%5E2%5D)
Step 4: Combing like terms

Step 5: Writing the final expression in standard form
