x加200/45等于x分之220乘以1/2x+200/45=(220/x)(1/2)x+40/9=110/xx²+40x/9=110x²+40x/9+(20/9)²=8910/81+400/81(x+20/9)²=9310/81x+20/9=±7√190/9x=-20/9±7√190/9=(-20±7√190)/9
