Question

Can you solve this problem???​

Answer 1

$( {p + q})^{4} - ( {p - q})^{4} \\ \\ = (( { {p + q})^{2} })^{2} -( ( { {p - q})^{2} })^{2} \\ \\ = (( {p + q})^{2} + ( {p - q})^{2} )(( {p + q})^{2} - ( {p - q})^{2} ) \\ \\ = (2( {p}^{2} + {q}^{2} ))(4pq) \\ \\ = 8pq( {p}^{2} + {q}^{2} )$