Here is a visual comparison between Matthew 3:1-7 and Luke 3:1-22. It is obvious that Matthew and Luke are using a common source. It is also obvious that they have very different agendas when telling this story.
The green underline is when they quote verbatim (exactly word for word). The orange wavy underline is when they say similar things, but the wording is different. The purple indicates parts that are unique to Matthew. The blue indicates parts that are unique to Luke.
What do you observe as you notice the similarities and contrasts? (feel free to download and use this graphic)