how is it possible to figure out a science problem like this EXAMPLE:s=2m*6Hz=2m*6(1/s)=12m/s
if they don't tell you what the letters mean?
That particular formula predicts the speed of a wave (s) ad the product of wavelength (L = 2 meter) and frequency (f = 6 Hz = 6 1/s)
They should have defined the terms for you. In your case, the variables for wavelength and frequency do not even appear. You went directly to the computation itself.
Sometimes when doing science problems, you have to define terms as you go along. Not everyone uses the same symbols. Often, journal articles and textbooks will use Greek symbols that I cannot even type here, such as lower case nu for frequency and lower case lambda for wavelength.