修一段420米的公路，每天修80米，修了4天后剩下的每天多修20米，剩下的几天修完？6z6o(\-q;a.F*D(z0G2n7M/x*G-f:z7Y
算式：提示*V;\)S4x2B0M)`2r6z6o(\-q;a.F*D(z0G2n7M/x*G-f:z7Y
答：剩下的:_0|3T2l天修完。6z6o(\-q;a.F*D(z0G2n7M/x*G-f:z7Y