Remove the brackets
-5a + 9b + 7a combine -5a and 7a
7a - 5a + 9b
2a + 9b Answer
Don't go any further. There is nothing else to do. These are unlike terms and cannot be reduced or combined.
The answer is P=F/A I had a quiz on these
The population in the above situation is the total number of students under Mr. Wilson.
A sample is a part of the population that may best represent the population. There is no sample in the above situation because Mr. Wilson made all students pick 5 note cards. He will be able to determine the performance of each student based on their performance in picking 5 note cards and defining the terms in each card.