i dont know if you want me to answer them or not, but you have to COMBINE LIKE TERMS if you dont then your problems would be messed up example if you have a+a it would be 2a make sense? so you want everything combined then you have to solve. theres no possible way of solving these without numbers number would have to be added although youll probably end up getting rid of the numbers in the end. after you combine like terms do the rest of solving
hope that helps if you need more help pm me, :)
2000, you just need to put three zeros at the end of the number.
Answer: Tammy's sample may not be vaild because she surveyed the students only from her class and it is likely that other classes might not like the subject maths. She might get the accurate results by surveying a larger number of people in the school instead of just her class.