Answer:
(p+e)/(r-n) = x
Explanation:
p + nx=rx-e
Add e to each side
p +e+ nx=rx-e+e
p +e+ nx=rx
Subtract nx from each side
p +e+ nx - nx=rx-nx
p+e = rx -nx
Factor out x
p+e = x(r-n)
Divide each side by (r-n)
(p+e)/(r-n) = x(r-n)/(r-n)
(p+e)/(r-n) = x