Question

I help with #2 on the worksheet & dividing the electric potential energy formula, so I can find what -q, E, and d are equal to.

Answer 1

$$
\triangle x=5~m\\
E=100~N/C\\
\triangle Pe_{electric}=-4(10)^{16}~J\\
q=-{\triangle Pe_{electric}\over E~\triangle x}
$$
Does this make sense?

Answer 2

so -q cancels out to make it postitive right

Answer 3

That's right.