6.45%x+（400000-x）*5.60%=24950 0.0645x+（400000-x）*0.056=24950 0.0645x+400000*0.056-0.056x=24950 0.0085x+400*56=24950 0.0085x=24950-22400 0.0085x=2550 85x=25500000 x=25500000/85 x=25500000/85 x=3000...