Answer:
13
Step-by-step explanation:
Set Susan's present age as x, her age from 3 years ago as x-3, and her age in three years as 2(x-3)
Since her age in seven years = 2 times as old as she way 3 years ago, set up the equation:
x+7 = 2(x-3)
x+7 = 2x-6
x = 13
In an arithmetic sequence, the difference between consecutive terms is constant. In formulas, there exists a number
such that

In an geometric sequence, the ratio between consecutive terms is constant. In formulas, there exists a number
such that

So, there exists infinite sequences that are not arithmetic nor geometric. Simply choose a sequence where neither the difference nor the ratio between consecutive terms is constant.
For example, any sequence starting with

Won't be arithmetic nor geometric. It's not arithmetic (no matter how you continue it, indefinitely), because the difference between the first two numbers is 14, and between the second and the third is -18, and thus it's not constant. It's not geometric either, because the ratio between the first two numbers is 15, and between the second and the third is -1/5, and thus it's not constant.
Answer:
B.
Step-by-step explanation:
The problem is saying 2/5 squared by -2 times -3 multiplied by itself 4 times.
2/5 multiplied by itself -2 times looks like this: -2/5 times -2/5.
-3 multiplied by itself 4 times looks like this: -3 times -3 times -3 times -3.
Put the two together and it looks like B.
Answer:
1/10
Step-by-step explanation:
1/2 divided by 5 = 1/10
Remember
i²=-1 so
i³=-i
i⁴=1
so
5i⁴+2i³+8i²-4
5(1)+2(-i)+8(-1)-4
5-2i-8-4
-7-2i is the form