[질문] xy=5이고x제곱y+xy제곱+2(x+y)=42일때x제곱+y제곱의값은?

x제곱+y제곱=(x+y)-2XY=(x+y)-10 *x제곱y+xy제곱+2(x+y)=42 =xy(x+y)+2(x+y)=42 =7(x+y)=42 따라서 답은 26