x1+x2=5;x1x2=1;(1)x1/x2+x2/x1=(x1²+x2²)/(x1x2)=((x1+x2)²-2x1x2)/(x1x2)=(25-2)/1=23;(2)x1²+5x2=x1²+5(5-x1)=x1²-5x1+25=-1+25=24;很高兴为您解答,skyhunter002为您答疑解惑如果...