The total amount I’m willing to spend is $400, to make the scarves it cost $5 to make the beanies it cost $3.

Write a Inequality that represents the fact while making each item you can’t exceeded this limit, be sure to include the cost per item in this inequality

Let 'x' represent the number of scarves and 'y' represent the number of beanies.

The cost per scarf is $5, so the cost of 'x' scarves would be 5x.
The cost per beanie is $3, so the cost of 'y' beanies would be 3y.

Since you cannot exceed the limit of $400, the inequality would be:
5x + 3y ≤ 400