Answer:
Frequency, 
Explanation:
Wavelength of a light wave is 450 nm. It is required to find the frequency of this light wave. The speed of light is given by c. So,

f is the frequency of this light

So, the frequency of this light is
.
You want to use PEMDAS to solve this equation.
4+9*2/3-1
4+18/6-1
4+6-1
10-1
9
Your answer is 9
Thanks -John
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The answer is reverse faults.