Someone answer this or at least explain this to me !

calculate the wavelength of the laser light for a) d = 1/500 mm and b) d = 1/1000 mm. use the modified “grating equation” given below:
nλ = d (x/l)
remember to keep all calculations in millimeters (mm) until the end and then convert your answer to nanometers (1 nm = 10‐6mm)

A. 127 cm^2 b. 144.5 cm^2 c. 172 cm^2 d. 50 cm^2

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of california was approximately two times the population of florida. b. the population of florida was approximately twenty times the population of california. c. the population of florida was approximately two times the population of california. d. the population of california was approximately twenty times the population of florida.

12 3 4 5 6 7 8 9 10time remaining01: 24: 54which graph represents this system? y=1/2x + 3 y= 3/2x -1