Hi, thank you for posting your question here at Brainly.
To find the velocity of light or any electromagnetic wave, we use the equation: v = wavelength * frequency. Substituting,
v = 0.5 m * 930 1/s
v = 465 m/s
The value of x will be obtained as follows:
1331x^4-216=0
1331x^4=216
divide through by 1331
x^4=216/1331
x=(216/1331)^(1/4)
x=(6^3/11^3)^(1/4)
x=(6/11)^(3/4)
4 2/3 is equal to 4 8/12. 3 and 1/4 is equal to 3 3/12. 4 8/12- 3 3/12 = 1 5/12. 1 1/2 would be a better estimate.