It looks like you've uploaded an image with a math problem in it. Let me take a moment to analyze the content and provide a solution.The problem in the image appears to involve a scenario where a store is selling two types of tools, A and B. The cost and sales quantities of these tools are related to a variable, and the task requires solving multiple aspects related to maximizing profits based on given constraints.

Here’s the breakdown of the problem:

1. Part (1) asks to find the relationship between the quantity of items sold and the price for two types of tools (A and B), given their cost and the quantity sold (represented as $y$ and $x$ respectively).
2. Part (2) requests to determine how the daily profit for two types of tools will change as the price for A increases by 4 yuan compared to B, and the relationship between the quantities sold needs to be modeled.
3. Part (3) involves maximizing the total profit given the constraints of daily sales for A and B, such as the total number of items sold and the total revenue.

There is also a graph provided that seems to show the relationship between the quantities of items sold.

To assist you in solving these problems, I can guide you step-by-step through each calculation.

Would you like to proceed with solving the first part?