Tomatoes are $5 a kilogram and potatoes are $6 a kilogram. What is the total cost ofx kilograms of tomatoes and z kilograms of potatoes?

The total cost of x kilograms of tomatoes and z kilograms of potatoes can be calculated as follows:

Step 1: Multiply the cost per kilogram of tomatoes ($5) by the number of kilograms (x). This gives you the total cost of the tomatoes. So, the cost of the tomatoes is 5x dollars.

Step 2: Multiply the cost per kilogram of potatoes ($6) by the number of kilograms (z). This gives you the total cost of the potatoes. So, the cost of the potatoes is 6z dollars.

Step 3: Add the total cost of the tomatoes and the total cost of the potatoes together to get the total cost. So, the total cost is 5x + 6z dollars.