0.6x+ 1. 1(80-x)& lt； =69
0.9x+0.4(80-x)& lt； =52
The solution is 38
Because X is a natural number, X can only take 38, 39 and 40.
Scheme 1: produce 38 A-type handicrafts and 42 B-type handicrafts;
Scheme 2: produce 39 A-type handicrafts and 4 1 B-type handicrafts;
Scheme 3: make 40 A-type handicrafts and 40 B-type handicrafts;
Suppose X pieces of A-type handicrafts are produced, then 80-x pieces of B-type products are produced.
y=45x+50(80-x)
y=45x+4000-50x
y=-5x+4000
Because a < 0, from the nature of linear function, y decreases with the increase of x 。
Therefore, at 38
When x=38, the maximum value of y is =38 10/0.
Therefore, scheme 1 should be adopted.
y=(45+a)x+50(80-x)
=(a-5)x+4000
When a-5
Therefore, scheme 1 should be adopted.
When a-5 >; =0, that is, a> When =5, from the nature of linear function, y increases with the increase of x.
Option 3 should therefore be adopted.