What is the 10th term in 4,8,16,32,64

2048

Explanation:

In order to get the next number, you are multiplying the last number by 2.

[1] 4

· 2

[2] 8

· 2

[3] 16

· 2

[4] 32

· 2

[5] 64

· 2

[6] 128

· 2

[7] 256

· 2

[8] 512

· 2

[9] 1024

· 2

[10] 2048

The correct option is: Option (B) Trevor isn't correct because -2i must also be a root

Explanation:
The roots given are: -7, 2i, +7.

We need to differentiate between the real roots and the imaginary roots.

The real roots are: -7 and +7.
The imaginary root given is: 2i

However, the imaginary roots ALWAYS come in pair like 
Because the imaginary roots come from the square root; In this case, the roots might be in the form of: . The square-root of the negative number yields the imaginary numbers (which can be positive or negative), which in this case is +2i and -2i.

Hence the correct answer is that Trevor isn't correct because -2i must also be a root (Option b).