An imaginary number is a complex number that can be written as a real number multiplied by the imaginary unit i, which is defined by it's property i² = −1. The square of an imaginary number bi is −b². For example, 5i is an imaginary number, and it's square is −25.
Is BC=2.3 one of the options?
For that question, you can use the cosine rule, where;

In this case, we have..

Solving for BC with this will get you 2.250406, rounded off to the tenth is 2.3.
The answer to 1 is common multiple. And the answer to 2 is common denominator
Answer:
p=1
Step-by-step explanation:
Rearrange terms
Combine multiplied terms into a single fraction
Subtract 2/5 from both sides of the equation
Simplify
Multiply all terms by the same value to eliminate fraction denominators
sorry if its wrong