80-40x=60 -40x=60-80 (移项) -40x=-20(负负得正 两边同乘1/40 然后约分) x=1/2
80-40X=60解: 40X=80-60 40X=20 X=20÷40 X=0.5
40X=80-6040X=20X=1/2