You just need to substitute 20 for x and then solve.
a(20) = -5 +(20-1)3
Simplify: a(20) = -5 + (60-3)
Simplify: a(20) = -5 + 57
Result: a(20) = 52
So, 52 is the 20th term of the arithmetic sequence.
They own a total of 120 CDs.
GIVEN:
Ella: ratio of rock music to total CDs that she owns 25/40
Paolo: has 50 rock music CDs. The ratio of rock music to total CD is equal to Ella's ratio.
Proportion: a/b = c/d where ad = bc
25/40 = 50/x
25x = 40 * 50
25x = 2000
25x / 25 = 2000 / 25
x = 80 total of Paolo's CDs
Total of Ella's CDs = 40
Total of Paolo's CDs =<u> 80</u>
Total CDs in all 120
4x - 2y = 10
-2y = -4x + 10
y = 4/2x - 10/2
y = 2x - 5 <==
The answer is the first data set because remember, an outlier is a number in a data set that is extremely far away from all of the other numbers.
You can easily tell which one is the outlier, the first data set's outlier is 13, because it is was placed so far away from the other data points.
We know that the first data set is correct because all of the other data sets have numbers that are clustered together.
~Hope I helped!~