How do you answer a task 1 question that has more than one chart or graph?
Here's my advice:
Write your introduction in the usual way: paraphrase the question. For this kind of question, it's easier to write 2 sentences e.g. "The first chart illustrates... The second chart shows..."
Write a paragraph describing the main points. If possible, try to summarise all of the information, rather than writing a separate summary for each chart. Look for a topic or trend that links the charts.
Describe each chart separately. Just write a short paragraph about each chart. Choose the most important information from each one.