甲筐苹果原来有x个3(x-20)=x+20x=40甲筐苹果原来有40个
x-20=(x+20)*1/3 x-20=1/3x+20/3 2/3x=20+20/3 x=3/2*80/3=40 1。甲筐苹果原来有40个用分数表示40/1
