Answer: 5. (1) Set up a walkman with X yuan and a schoolbag with Y yuan.

X+y=452 x=4y-8 If you substitute 2 into 1, you get 4y-8+y=452, y=92 and x=360.

(2) If you buy it in A, it will cost 452*0.8=36 1.6 yuan.

If you buy it at B, 452-30=422 yuan.

So it's cheaper for him to buy it in the supermarket.