Maria said the expression - 5n+ 2 + 8n - 9 is equivalent to - 4n. What error did Maria likely make?
1) She multiplied all the numbers instead of adding or subtracting.
2) She did not group like terms correctly. She combined all of the numbers in the expression even though they are not all coefficients of n.
3) She combined only the coefficients of n.
4) She did not group like terms correctly. She combined only the first two numbers.