Carlos's graph of the rational function f(x)=x2−7x+10x2−x−20 is below. His graph is used to help him navigate an underwater cave. Carlos lists values to check his graph of the rational function and discovers that his graph has a hole that he overlooked. The actual cave has a boulder at the location of the hole, and Carlos will have to swim around the boulder. What is the x value at the boulder's location? Enter the value in the blank.