(3x+2)分之(9x+7)-(2x+3)分之(4x+5)=1[(3x+2)(2x+3)]分之[(9x+7)(2x+3)-(4x+5)(2x+3)]=1(6x²+13x+6)分之[(18x²+41x+21)-(8x²+22x+15)]=1(6x²+13x+6)分之(10x²+19x+6)=110x²+19x+6=6x&...这些都是初中知识啊！