Answer:
The selling price is $79.53 .
Step-by-step explanation:
Formula

Let us assume that the cost price be x .
As given
Judy Garland Electronics operate on a net-profile rate of 20% on its printer cables.
If the markup is $8.95 and the overhead is $4.31 .
Selling price = Cost price + Markup price + Overhead price
Putting all the values in the above
= x + 8.95 + 4.31
= x + 13.26
Profit = Selling price - Cost price
= x + 13.26 - x
= 13.26
Putting all the values in the above




x = $ 66.3
Thus
Selling price = x + 13.26
= 66.3 + 13.26
= $ 79.53
Therefore the selling price is $79.53 .
Your answer would be the last option, c = √(E/m).
We can see this when we rearrange the equation, as:
E = mc²
÷ m
E/m = c²
√
√(E/m) = c
So you got all the steps in rearranging correct :)
I hope this helps!