H is 2t
h + t = 84
2t + t = 84
3t =84
t = 28
Thomas is 28 and huilan is 56
Answer: The first option
Step-by-step explanation:
I'm smart
Answer:
The principal square root of -4 is 2i.
Step-by-step explanation:
= 2i
We have the following steps to get the answer:
Applying radical rule 
We get 
As per imaginary rule we know that 
= 
Now 
Hence, the answer is 2i.