Then x+y = 8 (1)

5x+ 10y≥60 ② Note: The total number of bedsteads of the two models should not be less than 60.

20x+ 10y≥ 100 ③

③-① x≥2

③-② y≥4

Combined with the formula 1, there are three schemes: x=2, y = 6；;

x=3，y = 5；

x=4，y=4 .

(2) When x = 2 and y=6, the freight y =1200× 2+1000× 6 = 8,400 yuan.

When x=3 and y=5, the freight y =1200× 3+1000× 5 = 8600 yuan.

When x=4 and y=4, the freight y =1200× 4+1000× 4 = 8800 yuan.

Therefore, choosing x=2 and y=6 can make the freight lowest, which is 8400 yuan.

(p.s. It's all easier to explain. In fact, because the unit price of A is higher than that of B, the minimum value of A must be chosen. )