Answer:
$60 for a noble fir, and $40 for a douglas fir
Step-by-step explanation:
Let x represent the number of noble fir trees
Let y represent the number of douglas fir trees
We can set up a system of equations to solve this problem
5x + 3y = 420
12x + 9y = 1080
We can use elimination method to solve this. 9 is a multiple of 3, so we'll multiply the first equation by -3 to get...
-15x - 9y = -1260
12x + 9y = 1080
Now add them together...
-3x = -180 now solve for x...
x = 60
If x = 60, them
5(60) + 3y = 420 now solve for y
300 + 3y = 420
3y = 120
y = 40
Answer:
y^2+x^2=25
Step-by-step explanation:
The formula for the equation of a circle is (y-(y coordinate of circle))^2 + (x-(x coordinate of circle))^2=radius^2. Sorry if this is unclear, PM me if you need more explanation!
Answer:
9 words per minute
Step-by-step explanation:
Theres 72 words in 8 minutes, so to get her words to minute ratio you do 72 divided by 8 to get 9, words per minute.
Answer:
Option b) r = 0.70
Step-by-step explanation:
We are given the following in he question:
Variables:
x = the number of hours spent studying for a test
y = the number of points earned on the test
- Correlation is a technique that help us to find or define a relationship between two variables.
- A positive correlation means that an increase in one quantity leads to an increase in another quantity
- A negative correlation means with increase in one quantity the other quantity decreases.
- +1 tells about a a perfect positive linear relationship and −1 indicates a perfect negative linear relationship.
- Values between 0 and 0.3 tells about a weak positive linear relationship, values between 0.3 and 0.7 shows a moderate positive correlation and a correlation of 0.7 and 1.0 states a strong positive linear relationship.
- Values between 0 and -0.3 tells about a weak negative linear relationship, values between -0.3 and -0.7 shows a moderate negative correlation and a correlation value of of -0.7 and -1.0 states a strong negative linear relationship.
As the number of hours increases, the number of points earned on the test increases. Thus, the two variables are positively correlated.
Thus, the coefficient correlation between two variables can be given by r = 0.70, that shows a moderate positive correlation.
Option b) r = 0.70
As the new mathematical operation is defined by a△b=a^2-b/b-a^2, the value of 4△3 using the same operation will be 4△3 = -1
As per the question statement, we are given a new mathematical operation a△b=a^2-b/b-a^2 and we are supposed to find the value of 4△3 using the same operation.
Given, a△b=a^2-b/b-a^2
now 4△3 = (4^2-3) / (3-4^2)
4△3 = (16-3) / (3-16)
4△3 = 13 / -13
4△3 = -1
Hence, as the new mathematical operation is defined by a△b=a^2-b/b-a^2, the value of 4△3 using the same operation will be 4△3 = -1.
- Mathematical operation: An operator in mathematics is often a mapping or function that transforms components of one space into elements of another.
To learn more about mathematical operation, click on the link given below:
brainly.com/question/8959976
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