3 number of days are given form different activities of sales and purchase.
Day 2:
Earnings : $16
Spendings : $7.
Day 3:
Earnings : $22
Spendings : $12.
Please note: We always add the Earnings and Subtract the Spendings.
Therefore, the expression can be used to model the situation for these 2 days as
First day earning - First day spendings + Second day earning - Second day spendings
16-7 + 22 -12.
In order to write the expression as adding the additive inverse, we need to factor out minus from second group by making expression into two groups.
We will write two positive numbers in first group and two negative numbers in second group.
(16+22) + (-7-12).
Factoring out minus sign from second group, we get
(16+22) - (7+12)
This expression in additive inverse form now.
Step-by-step explanation: The middle quartile or <em>second quartile</em> as I like to call it is the median of the entire data set. Remember that the median is the middle number when the data is written from least to greatest.
This is the concept of algebra, to solve the expression we proceed as follows;
cos 2x-cosx=0
cos 2x=cosx
but:
cos 2x+1=2(cos^2x)
thereore;
from:
cos 2x=cos x
adding 1 on both sides we get:
cos 2x+1=cos x+1
2(cos^2x)=cosx+1
suppose;
cos x=a
thus;
2a^2=a+1
a^2-1/2a-1/2=0
solving the above quadratic we get:
a=-0.5 and a=1
when a=-0.5
cosx=-0.5
x=120=2/3π
when x=1
cos x=1
x=0
the answer is:
x=0 or x=2/3π
