The answer to question 9 is 5y. You do this by doing +8y and taking away -3y. It's the sane as doing 8-3 as you are just combing the related numbers. Using this theory, 10 is 10x²-4, 11 is 2a^5+5b and 12 is 2+8m+4n
Answer: (9) 5y (10) 20x - 1 (11) 32a + 5b (12) 8m + 2 + 4n
