Answer:
y - x = - 2 b
Step-by-step explanation:
Given-
3 x + 2 y = 5 a + b...................(i)
4 x - 3 y = a + 7 b.....................(ii)
<em><u>Multiply by 3 and 2 in equation (i) & (ii) respectively-</u></em>
<em><u>Add equation (iii) & (iv)-</u></em>
9 x + 6 y = 15 a + 3 a...................(iii)
<u>8 x - 6 y = 2 a + 14 b</u> ...................(iv)
17 x = 17 a + 17 b
<u>x = a + b</u>
Put x = a + b in equation (i)-
<em>2 y = 5 a + b - 3 a - 3 b</em>
<em>2 y = 2 a - 2 b</em>
<u>y = a - b </u>
<em>∴ y - x = a - b - ( a + b )</em>
<em>y - x = a - b - a - b</em>
y - x = - 2 b
Im not exactly sure but i think:
r^2+6r+2
________
5r^2-5r-25
remember IM NOT SO SURE
Answer:
The relative frequency is found by dividing the class frequencies by the total number of observations
Step-by-step explanation:
Relative frequency measures how often a value appears relative to the sum of the total values.
An example of how relative frequency is calculated
Here are the scores and frequency of students in a maths test
Scores (classes) Frequency Relative frequency
0 - 20 10 10 / 50 = 0.2
21 - 40 15 15 / 50 = 0.3
41 - 60 10 10 / 50 = 0.2
61 - 80 5 5 / 50 = 0.1
81 - 100 <u> 10</u> 10 / 50 = <u>0.2</u>
50 1
From the above example, it can be seen that :
- two or more classes can have the same relative frequency
- The relative frequency is found by dividing the class frequencies by the total number of observations.
- The sum of the relative frequencies must be equal to one
- The sum of the frequencies and not the relative frequencies is equal to the number of observations.
0.31 = 31%
% is out of 100 so 31% is 31 out of 100 which is 31/100 :)
