Question 34440
Mr./Ms. Strawberry is correct in their statement about YOUR answer, however there was a mistake in their work as well, not in the final answer, but the work getting to the final answer.


It should do like this, actually (pay attention to terms and exponents to see the actual difference)...

{{{(m^2+n^2-mn)(m^2+mn+n^2)}}}
= {{{m^2(m^2+mn+n^2) +n^2(m^2+mn+n^2) -mn(m^2+mn+n^2)}}}
= {{{m^4 + m^3n + m^2n^2 + m^2n^2 + mn^3 + n^4 - m^3n - m^2n^2 - mn^3}}}


IF the problem says collect like terms; then the answer should turn out to be like this: {{{m^4 + m^2n^2 + n^4}}}