I’m going to say multiply both sides by a which gives you:
a^2-ab-a=2
If not give me a call
If $26 represents the cost of the 5 used CDs, than your formula would be "26+4x" ,x being the amount of extra CDs you purchase.
The number CDs minus 5 is our x value, because the first 5 are the used CDs bundled into the $26 group.
26+4(6-5)
26+4(1)
26+4
30
6 CDs would cost $30
Given series is 2.4,-4.8,9.6,-19.2
To find whether it has common difference or common ratio let us find few differences and few ratios of consecutive terms.
Common difference of first 2 terms = 2nd term - first term = -4.8-2.4 = -7.2
Common difference of 2nd and 3rd terms = 3rd term - 2nd term = 9.6-(-4.8) = 14.4
Since those common differences are not equal the given series does not have common difference at all.
To check if it has common ratio or not let us find few ratios of consecutive terms.
Common ratio of first 2 terms =
= 
Common ratio of 2nd and 3rd terms = 
So, the given series has common ratio as -2.0
D and B
Explanation:
when you look at that point two lines pass through it and those two lines that pass through it are b and d.