Given:

You know that:

In order to solve the operation, you can follow these steps:
1. Distribute the negative signs. Remember the Sign Rules for Multiplication:

Then:

2. Combine the like terms (add the Real Parts and add the Imaginary Parts):

Hence, the answer is: Option B.
Answer:
Step-by-step explanation:
The green arrow thing is a ray. So, question b. is a ray. So the dot would be B and the arrow would be C.
Answer:
b=-2aH
Step-by-step explanation:
H=-b/2a
Apply cross multiplication
H×2a=-b
2aH=-b
In the question you are to find positive b not negative b so you have to take negative b to the left hand side of the equation to become positive b and take 2aH to the right hand side to become -2aH
therefore b=-2aH
Answer:
60
Step-by-step explanation:
Just use similar triangles.
12/10 = 72/x
Now solve for x.
x = 72 * 10 / 12 = 60