Answer:
6 x + 23 y  < $ 680  represents the combinations of x balls and y nets that can be purchased.
Step-by-step explanation:
The number of balls than can be purchased  = x
The number of nets than can be purchased  = y
Total savings  = $ 680
Now, the cost of 1 ball =$6
So, the cost of x balls = x ( cost of 1 ball) = x ( $6)  = 6 x
Also, the cost of 1 net =$23
So, the cost of y nets = y ( cost of 1 net = y ( $23)  = 23 y
So, the total amount spent on x balls  and y nets 
= Amount spent on x balls + Amount on y nets
 =  6 x + 23 y 
Also, the saved amount is $680
⇒<u> 6 x + 23 y  < $ 680</u>
Hence, 6 x + 23 y  < $ 680  represents the combinations of x balls and y nets that can be purchased.