Question 26949
First, multiply both sides by 100p, obtaining:

{{{100p-4000 = 0.3*(100p)}}}

Subtract {{{0.3*(100p)}}} from both sides and add {{{4000}}} to both sides:

{{{100p - 0.3(100p) = 4000}}}

Take 100p as common factor

{{{100p(1-0.3) = 4000}}}

{{{100p0.7 = 4000}}}

{{{70p = 4000}}}

Finally, divide both sides by 70

{{{p = 4000/70 = 57.1428...}}}