Okay this one is easy all you gotta do is look at the decimal point and the place its at.
Hey!! I got 90cm for the answer
Answer:
The mean for the second week is $2 less than the first and in percentage it is 22% less.
Step-by-step explanation:
The mean is given by the sum of all individual values divided by the number of values. For the first week the sum is:
sum1 = 6.5 + 8 + 7.25 + 13.5 + 9.75
sum1 = 45
Since she spent 10 less in the second week the sum is:
sum2 = sum1 - 10 = 45 - 10 = 35
The mean for each week is:
mean1 = sum1/5 = 45/5 = 9
mean2 = sum2/5 = 35/5 = 7
difference = mean1 - mean2 = 9-7 = 2
difference(%) = [2/9]*100 = 0.22*100 = 22%
The mean for the second week is $2 less than the first and in percentage it is 22% less.
Since you need an isolated variable to use the substitution method, we need to re-arrange one of the equations. This will probably be easiest to do with the first one.
Add 5y to both sides of the first equation.
x=10+5y
Now, in the second equation, put in 10+5y in any spot that has an x.
2(10+5y)-10y=20
Distribute the 2 to both numbers in the parenthesis.
20+10y-10y=20
Combine like terms.
20=20
This means that the two equations are actually the same. You can see this if you multiply the whole first equation by 2
2(x-5y=10)
2x-10y=20, which is the same as the second equation. Therefore, the two equations are actually the same one.