设t=300/x300*(1+20%)/(t+5) +6=t360/t+5 +6=t360/t+5=t-6360=(t+5)*(t-6)t=10或3300/x=10或3x=30或100
(300+60)/(300/X+5)+6=300/X360/(300/X)+300/5+6=300/X360/300x+66=300/X自己做吧 貌似是一元二次
x=25.23