<span>A) 2x + 4y = 38
B) 10x + 3y = 105
Multiplying A) by -5
A) -10x -20y = -190 then adding it to B)
</span><span>B) 10x + 3y = 105
-17y = -85
y = 5
x = 9
</span>
Answer:
1.4222222222
Step-by-step explanation:
12 divided by 10 is 1.2. 15 multiplied by 1.2 is 18 so x equals 18
Answer:
P = 0.008908
Step-by-step explanation:
The complete question is:
The table below describes the smoking habits of a group of asthma sufferers
Nonsmokers Light Smoker Heavy smoker Total
Men 303 35 37 375
Women 413 31 45 489
Total 716 66 82 864
If two different people are randomly selected from the 864 subjects, find the probability that they are both heavy smokers.
The number of ways in which we can select x subjects from a group of n subject is given by the combination and it is calculated as:
Now, there are 82C2 ways to select subjects that are both heavy smokers. Because we are going to select 2 subjects from a group of 82 heavy smokers. So, it is calculated as:
At the same way, there are 864C2 ways to select 2 different people from the 864 subjects. It is equal to:
Then, the probability P that two different people from the 864 subjects are both heavy smokers is:
Answer:
(x - 5)(x + 3)
Step-by-step explanation:
to solve x² - 2x = 15, we need to get all the terms on one side so we can solve the quadratic equation using factoring. to do this, we subtract 15 from both sides
x² - 2x = 15
- 15 -15
x² - 2x - 15 = 0
now we can factor. we need 2 numbers that when multiplied together give us -15, and when those 2 numbers are added together we get -2
because we have a -15, we can assume that one number must be negative and the other positive, as a negative times a postive is a negative.
we can use 3 and -5 as factors and test it out. we put x in front because we have an x²
(x - 5)(x + 3) < we can FOIL to check to see if this is correct. its not mandatory to check but when you arent sure of the answer you can FOIL it out
FOIL stands for: First, Outside, Inside, and Last terms
F: (x - 5)(x + 3) = x²
O: (x - 5)(x + 3) = -3x
I: (x - 5)(x + 3) = 5x
L: (x - 5)(x + 3) = -15
x² + 3x - 5x - 15 < subtract 3x from 5x
x² - 2x - 15
this checks out, so our answer is (x - 5)(x + 3)
