设5%的为X(X*5%-X*5%*20%)+((500-X)*4%-(500-X)*4%*20%)=18.8X*5%*80%+(500-X)*4%*80%=18.80.04X+0.032(500-X)=18.80.04X+16-0.032X=18.80.008X=2.8X=350两种储蓄分别是350元和150元