Find each sum or difference

Question

(3x^2 + 7x- 2)+ (2x^2 - 3x + 4)
Answer: 5x^2 + 4x + 2

(4x + 8y) + (-7y + 3x)
Answer: 7x+1y

(x^2 + 4x - 1)+ (9x^2 - 8x + 9)
Answer: 10x^2 - 4x + 8

(8x + 6) - (2x - 1)
Answer: 6x+ 11

Answer 1

all are correct, except the last one. How did you get 6+1 to equal 11?

Answer 2

I'm sorry my answer is 6x + 7 is this right???

Answer 3

please read my correct answer

Answer 4

correct.