Question

(х²+у²)² помогите решить

Answer 1

$( x^{2} + y^{2} ) ^{2} = ( x^{2}) ^{2} + 2 x^{2} y^{2} + ( y^{2}) ^{2}= x^{4} +2 x^{2} y^{2} + y^{4}$