(1)甲类总收费为7+(x-3)•1.6=1.6x+2.2,
乙类总收费为6+(x-3)•1.4=1.4x+1.8;
(2)当x=6时,甲类需付费为1.6×6+2.2=11.8,不够,
乙类需付费为1.4×6+1.8=10.2<11,
∴他乘出租车到科技馆车费够.
(1)甲类总收费为7+(x-3)•1.6=1.6x+2.2,
乙类总收费为6+(x-3)•1.4=1.4x+1.8;
(2)当x=6时,甲类需付费为1.6×6+2.2=11.8,不够,
乙类需付费为1.4×6+1.8=10.2<11,
∴他乘出租车到科技馆车费够.