The question is missing. Here is the complete question.
One light beam has wavelength,
, and frequency, f₁. Another light beam has wavelength,
, and frequency, f₂. Write a proportion that shows how the ratio of the wavelengths of these two light beams is related to the ratio of the frequencies.
Answer:

Step-by-step explanation: In vacuum, eletromagnetic waves travels at a constant speed called "speed of light", whose symbol is [c] and magnitude is 3x10⁸m/s.
Speed of light, frequency and wavelength are related by the formula:

So, if one light beam has wavelength and frequency,
and f₁, respectively, the second beam has wavelength
and frequency f₂ and both travel at speed of light:


Then, the ratio that shows the relation between frequencies and wavelengths of these light beams is
