Somebody please help me I’m completely lost

λ [Wavelength] = 3.04357825 m [meters]

Explanation:

Given a frequency, to find the wavelength, divide the speed of light by the frequency. Wavelength = Speed Of Light In Seconds / Frequency .

Wavelength in meters is: λ = 299,792,458 m/s / f Hz .

Then substitute in the frequency to find the wavelength: λ = 299,792,458 m/s / f Hz → λ = 299,792,458 m/s / 9.85 × 10^7 Hz → λ = 2.99792458 × 10^8 m/s / 9.85 × 10^7 → λ = 2.99792458 × 10^8 m / 9.85 × 10^7 → λ = 29.9792458 / 9.85 m → λ = 3.04357825 m