Answer:
I didn't do the observation so I can't help sorry
Potassium it is the answer
When y equals 5, x is 104.3
When y equals 3 then x is 108.3
<em><u>Solution:</u></em>
<em><u>Given expression is:</u></em>

<h3><u>If y equals 5 what is x ?</u></h3>
Substitute y = 5 in given expression
5 = 57.15 - 0.5(x)
5 = 57.15 - 0.5x
0.5x = 57.15 - 5
0.5x = 52.15
Divide both sides by 0.5
x = 104.3
Thus when y equals 5, x is 104.3
<h3><u>If y = 3 what is x ?</u></h3>
Substitute y = 3 in given expression
3 = 57.15 - 0.5(x)
3 = 57.15 - 0.5x
0.5x = 57.15 - 3
0.5x = 54.15
Divide both sides by 0.5
x = 108.3
Thus when y equals 3 then x is 108.3
Answer:

Explanation:
We are supposed to find the frequency of light .
λf=c
the abow formula is the relation for frequency and wavelength.
Here c is the speed of light.

Given that
λ= 
by substituting all this we get f as,


Answer:
according to me option a is the correct one