$900, but not too sure if this is a question to trick you.
If your talking about solar power its because its just not practical solar power doesnt put out nearly enough power for us to be able to run widespread as of yet new and more efficient solar power inc
Step-by-step explanation:
y = 4 when x = 8 So, 4 = 8k
k = 1/2
y = (1/2)x
Therefore, when x = 10, y = (1/2)(10) = 5
