Cara has $25 to buy dry pet food a pound of dog food costs $2 and treats are $1 apiece if she buys 9 pounds of food the greatest number treats does know

Cost of each pound of dog food = $2.

Total cost of 9 pounds of dog food = 9 * 2 = $18.

Let us assume number of treats she can buy = t.

Cost of each treat = $1.

Cost of t number of treats = 1*t = 1t.

Total money Cara has = $25.

We can setup an inequality as,

Total cost of dog food + total cost of t number of treats ≤ 25.

18 + 1t ≤ 25.

Subtracting 18 from both sides, we get

18 + 1t - 18 ≤ 25-18.

1t ≤ 7 or t ≤ 7.

So, she can purchase 7 or less treats.