What can cause an extraneous solution when dealing with rational equations?

The table shows the results of three plays in a football game. what is the net result of the three plays? football game 1st play 5 yards 2nd play -9 yards 3rd play 12 yards

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

The table shows the number of students who signed up for different after school activities. activity students cooking 9 chess 4 photography 8 robotics 11 select the true statements about the information in the table.