1）甲 7+1.6（X-3）=1.6X+2.2 乙6+1.4（X-3）=1.4X+1.82）乘甲种车要1.6X+2.2=1.6x6+2.2=11.8元乘乙种车要1.4X+1.8=1.4x6+1.8=10.2元乘乙种车就够，乘甲种车就不够
