Answer:
Ваша глупость
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
The correlation coefficient r=-0.84 denotes that there is inverse relationship between x and y. It means that as the x values increase the y values decrease whereas as the x values decreases the y-values increases. Also, r=-0.84 denotes the strong relationship between x and y because it is close to 1. So, r=-0.84 denotes that there is strong linear relationship between x and y with smaller x values tending to be associated with larger y values.
Answer:
75% bigger
Step-by-step explanation:
Let the first number be x and the second be y.
So:

And:
-----30% less than x
Substitute
in 




Cross multiply


Collect like terms


Make x the subject


So, the average is:




Rewrite as:

Express as percentage

This means that the average is 75% bigger than the second number
Call the notebooks x, and the pencils y.
<span>3x + 4y = $8.50 and 5x + 8y = $14.50 </span>
<span>Then just solve as simultaneous equations: </span>
<span>3x + 4y = $8.50 </span>
<span>5x + 8y = $14.50 </span>
<span>5(3x + 4y = 8.5) </span>
<span>3(5x + 8y = 14.5) </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 24y = 43.5 </span>
<span>Think: DASS (Different Add, Similar Subtract). 15x appears in both equations so subtract one equation from the other. Eassier to subtract (15x + 20y = 42.5) from (15x + 24y = 43.5) </span>
<span>(15x + 24y = 43.5) - (15x + 20y = 42.5) = (4y = 1) which means y = 0.25. </span>
<span>Then substitue into equation : </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 5 + 42.5 </span>
<span>15x = 42.5 - 5 = 37.5 </span>
<span>15x = 37.5 </span>
<span>x = 2.5 </span>
<span>15x + 24y = 43.5 </span>
<span>15(2.5) + 24(0.25) </span>
<span>37.5 + 6 = 43.5 </span>
<span>So x (notebooks) are 2.5 ($2.50) each and y (pencils) are 0.25 ($0.25) each.</span>