解:1/5x+500=40%x1/5x+500=2/5x2/5x-1/5x=5001/5x=500x=500*5x=2500
1/5x+500=40%x因为40%x=2/5x1/5x+500=40%x1/5x+500=2/5x500=2/5x-1/5x500=1/5xx=2500
解方程:1/5x+500=40%x1/5x-40%x=-500-1/5x=-500x=2500